Seattle (SEA) to Ontario (ONT), April 2027: flights from $110 one way

Compare flight prices from Seattle to Ontario for your dates. There are no recent complete one-adult round trips here to set a price target.

Axel shows the exact bookable round-trip price from Seattle to Ontario for your dates, one traveler, no account to see it.

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Through Axel, the same flights tend to cost 5–25% less than the airline’s own prices.

Flights in April 2027

Lowest published fares in April 2027: $215 round trip, Axel-exclusive, Frontier Airlines, nonstop, Apr 5–8, 2027; $110 one way, Axel-exclusive, Frontier Airlines, nonstop, Apr 5, 2027; 180 priced flights on 90 exact dates, 1 adult, economy, checked Oct 29, 2026. Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

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Seattle (SEA) to Ontario (ONT): April 2027

Travel dates	Airline	Stops	Total price
Apr 1, 2027 · One way · Compare return dates departing Apr 1, 2027	Frontier Airlines	Nonstop	Axel-exclusive $132.00
Apr 1, 2027 · One way · Compare return dates departing Apr 1, 2027	Alaska Airlines	Nonstop	Axel-exclusive $210.00
Apr 1, 2027 – Apr 4, 2027 · 3 nights · Compare return dates departing Apr 1, 2027	Frontier Airlines	Nonstop	Axel-exclusive $258.00
Apr 1, 2027 – Apr 4, 2027 · 3 nights · Compare return dates departing Apr 1, 2027	Alaska Airlines	Nonstop	Axel-exclusive $406.80
Apr 1, 2027 – Apr 8, 2027 · 7 nights · Compare return dates departing Apr 1, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 1, 2027 – Apr 8, 2027 · 7 nights · Compare return dates departing Apr 1, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 2, 2027 · One way · Compare return dates departing Apr 2, 2027	Frontier Airlines	Nonstop	Axel-exclusive $132.00
Apr 2, 2027 · One way · Compare return dates departing Apr 2, 2027	Alaska Airlines	Nonstop	Axel-exclusive $210.00
Apr 2, 2027 – Apr 5, 2027 · 3 nights · Compare return dates departing Apr 2, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 2, 2027 – Apr 5, 2027 · 3 nights · Compare return dates departing Apr 2, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 2, 2027 – Apr 9, 2027 · 7 nights · Compare return dates departing Apr 2, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 2, 2027 – Apr 9, 2027 · 7 nights · Compare return dates departing Apr 2, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 3, 2027 · One way · Compare return dates departing Apr 3, 2027	Frontier Airlines	Nonstop	Axel-exclusive $132.00
Apr 3, 2027 · One way · Compare return dates departing Apr 3, 2027	Alaska Airlines	Nonstop	Axel-exclusive $210.00
Apr 3, 2027 – Apr 6, 2027 · 3 nights · Compare return dates departing Apr 3, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 3, 2027 – Apr 6, 2027 · 3 nights · Compare return dates departing Apr 3, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 3, 2027 – Apr 10, 2027 · 7 nights · Compare return dates departing Apr 3, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 3, 2027 – Apr 10, 2027 · 7 nights · Compare return dates departing Apr 3, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 4, 2027 · One way · Compare return dates departing Apr 4, 2027	Frontier Airlines	Nonstop	Axel-exclusive $132.00
Apr 4, 2027 · One way · Compare return dates departing Apr 4, 2027	Alaska Airlines	Nonstop	Axel-exclusive $210.00
Apr 4, 2027 – Apr 7, 2027 · 3 nights · Compare return dates departing Apr 4, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 4, 2027 – Apr 7, 2027 · 3 nights · Compare return dates departing Apr 4, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 4, 2027 – Apr 11, 2027 · 7 nights · Compare return dates departing Apr 4, 2027	Frontier Airlines	Nonstop	Axel-exclusive $236.50
Apr 4, 2027 – Apr 11, 2027 · 7 nights · Compare return dates departing Apr 4, 2027	Alaska Airlines	Nonstop	Axel-exclusive $372.90
Apr 5, 2027 · One way · Compare return dates departing Apr 5, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 5, 2027 · One way · Compare return dates departing Apr 5, 2027	Delta Air Lines	Nonstop	Axel-exclusive $180.00
Apr 5, 2027 – Apr 8, 2027 · 3 nights · Compare return dates departing Apr 5, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 5, 2027 – Apr 8, 2027 · 3 nights · Compare return dates departing Apr 5, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 5, 2027 – Apr 12, 2027 · 7 nights · Compare return dates departing Apr 5, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 5, 2027 – Apr 12, 2027 · 7 nights · Compare return dates departing Apr 5, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 6, 2027 · One way · Compare return dates departing Apr 6, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $140.00
Apr 6, 2027 · One way · Compare return dates departing Apr 6, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 6, 2027 – Apr 9, 2027 · 3 nights · Compare return dates departing Apr 6, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 6, 2027 – Apr 9, 2027 · 3 nights · Compare return dates departing Apr 6, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 6, 2027 – Apr 13, 2027 · 7 nights · Compare return dates departing Apr 6, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 6, 2027 – Apr 13, 2027 · 7 nights · Compare return dates departing Apr 6, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 7, 2027 · One way · Compare return dates departing Apr 7, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 7, 2027 · One way · Compare return dates departing Apr 7, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 7, 2027 – Apr 10, 2027 · 3 nights · Compare return dates departing Apr 7, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 7, 2027 – Apr 10, 2027 · 3 nights · Compare return dates departing Apr 7, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 7, 2027 – Apr 14, 2027 · 7 nights · Compare return dates departing Apr 7, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 7, 2027 – Apr 14, 2027 · 7 nights · Compare return dates departing Apr 7, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 8, 2027 · One way · Compare return dates departing Apr 8, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 8, 2027 · One way · Compare return dates departing Apr 8, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 8, 2027 – Apr 11, 2027 · 3 nights · Compare return dates departing Apr 8, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 8, 2027 – Apr 11, 2027 · 3 nights · Compare return dates departing Apr 8, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 8, 2027 – Apr 15, 2027 · 7 nights · Compare return dates departing Apr 8, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 8, 2027 – Apr 15, 2027 · 7 nights · Compare return dates departing Apr 8, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 9, 2027 · One way · Compare return dates departing Apr 9, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 9, 2027 · One way · Compare return dates departing Apr 9, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 9, 2027 – Apr 12, 2027 · 3 nights · Compare return dates departing Apr 9, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 9, 2027 – Apr 12, 2027 · 3 nights · Compare return dates departing Apr 9, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 9, 2027 – Apr 16, 2027 · 7 nights · Compare return dates departing Apr 9, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 9, 2027 – Apr 16, 2027 · 7 nights · Compare return dates departing Apr 9, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 10, 2027 · One way · Compare return dates departing Apr 10, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 10, 2027 · One way · Compare return dates departing Apr 10, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 10, 2027 – Apr 13, 2027 · 3 nights · Compare return dates departing Apr 10, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 10, 2027 – Apr 13, 2027 · 3 nights · Compare return dates departing Apr 10, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 10, 2027 – Apr 17, 2027 · 7 nights · Compare return dates departing Apr 10, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 10, 2027 – Apr 17, 2027 · 7 nights · Compare return dates departing Apr 10, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 11, 2027 · One way · Compare return dates departing Apr 11, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 11, 2027 · One way · Compare return dates departing Apr 11, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 11, 2027 – Apr 14, 2027 · 3 nights · Compare return dates departing Apr 11, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 11, 2027 – Apr 14, 2027 · 3 nights · Compare return dates departing Apr 11, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 11, 2027 – Apr 18, 2027 · 7 nights · Compare return dates departing Apr 11, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 11, 2027 – Apr 18, 2027 · 7 nights · Compare return dates departing Apr 11, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 12, 2027 · One way · Compare return dates departing Apr 12, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 12, 2027 · One way · Compare return dates departing Apr 12, 2027	Delta Air Lines	Nonstop	Axel-exclusive $180.00
Apr 12, 2027 – Apr 15, 2027 · 3 nights · Compare return dates departing Apr 12, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 12, 2027 – Apr 15, 2027 · 3 nights · Compare return dates departing Apr 12, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 12, 2027 – Apr 19, 2027 · 7 nights · Compare return dates departing Apr 12, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 12, 2027 – Apr 19, 2027 · 7 nights · Compare return dates departing Apr 12, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 13, 2027 · One way · Compare return dates departing Apr 13, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $140.00
Apr 13, 2027 · One way · Compare return dates departing Apr 13, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 13, 2027 – Apr 16, 2027 · 3 nights · Compare return dates departing Apr 13, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 13, 2027 – Apr 16, 2027 · 3 nights · Compare return dates departing Apr 13, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 13, 2027 – Apr 20, 2027 · 7 nights · Compare return dates departing Apr 13, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 13, 2027 – Apr 20, 2027 · 7 nights · Compare return dates departing Apr 13, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 14, 2027 · One way · Compare return dates departing Apr 14, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 14, 2027 · One way · Compare return dates departing Apr 14, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 14, 2027 – Apr 17, 2027 · 3 nights · Compare return dates departing Apr 14, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 14, 2027 – Apr 17, 2027 · 3 nights · Compare return dates departing Apr 14, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 14, 2027 – Apr 21, 2027 · 7 nights · Compare return dates departing Apr 14, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 14, 2027 – Apr 21, 2027 · 7 nights · Compare return dates departing Apr 14, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 15, 2027 · One way · Compare return dates departing Apr 15, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 15, 2027 · One way · Compare return dates departing Apr 15, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 15, 2027 – Apr 18, 2027 · 3 nights · Compare return dates departing Apr 15, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 15, 2027 – Apr 18, 2027 · 3 nights · Compare return dates departing Apr 15, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 15, 2027 – Apr 22, 2027 · 7 nights · Compare return dates departing Apr 15, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 15, 2027 – Apr 22, 2027 · 7 nights · Compare return dates departing Apr 15, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 16, 2027 · One way · Compare return dates departing Apr 16, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 16, 2027 · One way · Compare return dates departing Apr 16, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 16, 2027 – Apr 19, 2027 · 3 nights · Compare return dates departing Apr 16, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 16, 2027 – Apr 19, 2027 · 3 nights · Compare return dates departing Apr 16, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 16, 2027 – Apr 23, 2027 · 7 nights · Compare return dates departing Apr 16, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 16, 2027 – Apr 23, 2027 · 7 nights · Compare return dates departing Apr 16, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 17, 2027 · One way · Compare return dates departing Apr 17, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 17, 2027 · One way · Compare return dates departing Apr 17, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 17, 2027 – Apr 20, 2027 · 3 nights · Compare return dates departing Apr 17, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 17, 2027 – Apr 20, 2027 · 3 nights · Compare return dates departing Apr 17, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 17, 2027 – Apr 24, 2027 · 7 nights · Compare return dates departing Apr 17, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 17, 2027 – Apr 24, 2027 · 7 nights · Compare return dates departing Apr 17, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 18, 2027 · One way · Compare return dates departing Apr 18, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 18, 2027 · One way · Compare return dates departing Apr 18, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 18, 2027 – Apr 21, 2027 · 3 nights · Compare return dates departing Apr 18, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 18, 2027 – Apr 21, 2027 · 3 nights · Compare return dates departing Apr 18, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 18, 2027 – Apr 25, 2027 · 7 nights · Compare return dates departing Apr 18, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 18, 2027 – Apr 25, 2027 · 7 nights · Compare return dates departing Apr 18, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 19, 2027 · One way · Compare return dates departing Apr 19, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 19, 2027 · One way · Compare return dates departing Apr 19, 2027	Delta Air Lines	Nonstop	Axel-exclusive $180.00
Apr 19, 2027 – Apr 22, 2027 · 3 nights · Compare return dates departing Apr 19, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 19, 2027 – Apr 22, 2027 · 3 nights · Compare return dates departing Apr 19, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 19, 2027 – Apr 26, 2027 · 7 nights · Compare return dates departing Apr 19, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 19, 2027 – Apr 26, 2027 · 7 nights · Compare return dates departing Apr 19, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 20, 2027 · One way · Compare return dates departing Apr 20, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $140.00
Apr 20, 2027 · One way · Compare return dates departing Apr 20, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 20, 2027 – Apr 23, 2027 · 3 nights · Compare return dates departing Apr 20, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 20, 2027 – Apr 23, 2027 · 3 nights · Compare return dates departing Apr 20, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 20, 2027 – Apr 27, 2027 · 7 nights · Compare return dates departing Apr 20, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 20, 2027 – Apr 27, 2027 · 7 nights · Compare return dates departing Apr 20, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 21, 2027 · One way · Compare return dates departing Apr 21, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 21, 2027 · One way · Compare return dates departing Apr 21, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 21, 2027 – Apr 24, 2027 · 3 nights · Compare return dates departing Apr 21, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 21, 2027 – Apr 24, 2027 · 3 nights · Compare return dates departing Apr 21, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 21, 2027 – Apr 28, 2027 · 7 nights · Compare return dates departing Apr 21, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 21, 2027 – Apr 28, 2027 · 7 nights · Compare return dates departing Apr 21, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 22, 2027 · One way · Compare return dates departing Apr 22, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 22, 2027 · One way · Compare return dates departing Apr 22, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 22, 2027 – Apr 25, 2027 · 3 nights · Compare return dates departing Apr 22, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 22, 2027 – Apr 25, 2027 · 3 nights · Compare return dates departing Apr 22, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 22, 2027 – Apr 29, 2027 · 7 nights · Compare return dates departing Apr 22, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 22, 2027 – Apr 29, 2027 · 7 nights · Compare return dates departing Apr 22, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 23, 2027 · One way · Compare return dates departing Apr 23, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 23, 2027 · One way · Compare return dates departing Apr 23, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 23, 2027 – Apr 26, 2027 · 3 nights · Compare return dates departing Apr 23, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 23, 2027 – Apr 26, 2027 · 3 nights · Compare return dates departing Apr 23, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 23, 2027 – Apr 30, 2027 · 7 nights · Compare return dates departing Apr 23, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 23, 2027 – Apr 30, 2027 · 7 nights · Compare return dates departing Apr 23, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 24, 2027 · One way · Compare return dates departing Apr 24, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 24, 2027 · One way · Compare return dates departing Apr 24, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 24, 2027 – Apr 27, 2027 · 3 nights · Compare return dates departing Apr 24, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 24, 2027 – Apr 27, 2027 · 3 nights · Compare return dates departing Apr 24, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 24, 2027 – May 1, 2027 · 7 nights · Compare return dates departing Apr 24, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 24, 2027 – May 1, 2027 · 7 nights · Compare return dates departing Apr 24, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 25, 2027 · One way · Compare return dates departing Apr 25, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 25, 2027 · One way · Compare return dates departing Apr 25, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 25, 2027 – Apr 28, 2027 · 3 nights · Compare return dates departing Apr 25, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 25, 2027 – Apr 28, 2027 · 3 nights · Compare return dates departing Apr 25, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 25, 2027 – May 2, 2027 · 7 nights · Compare return dates departing Apr 25, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 25, 2027 – May 2, 2027 · 7 nights · Compare return dates departing Apr 25, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 26, 2027 · One way · Compare return dates departing Apr 26, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 26, 2027 · One way · Compare return dates departing Apr 26, 2027	Delta Air Lines	Nonstop	Axel-exclusive $180.00
Apr 26, 2027 – Apr 29, 2027 · 3 nights · Compare return dates departing Apr 26, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 26, 2027 – Apr 29, 2027 · 3 nights · Compare return dates departing Apr 26, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 26, 2027 – May 3, 2027 · 7 nights · Compare return dates departing Apr 26, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 26, 2027 – May 3, 2027 · 7 nights · Compare return dates departing Apr 26, 2027	Delta Air Lines	Nonstop	Axel-exclusive $349.00
Apr 27, 2027 · One way · Compare return dates departing Apr 27, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $140.00
Apr 27, 2027 · One way · Compare return dates departing Apr 27, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 27, 2027 – Apr 30, 2027 · 3 nights · Compare return dates departing Apr 27, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 27, 2027 – Apr 30, 2027 · 3 nights · Compare return dates departing Apr 27, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 27, 2027 – May 4, 2027 · 7 nights · Compare return dates departing Apr 27, 2027	Frontier Airlines	Up to 1 stop each way	Axel-exclusive $245.00
Apr 27, 2027 – May 4, 2027 · 7 nights · Compare return dates departing Apr 27, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 28, 2027 · One way · Compare return dates departing Apr 28, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 28, 2027 · One way · Compare return dates departing Apr 28, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 28, 2027 – May 1, 2027 · 3 nights · Compare return dates departing Apr 28, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 28, 2027 – May 1, 2027 · 3 nights · Compare return dates departing Apr 28, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 28, 2027 – May 5, 2027 · 7 nights · Compare return dates departing Apr 28, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 28, 2027 – May 5, 2027 · 7 nights · Compare return dates departing Apr 28, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 29, 2027 · One way · Compare return dates departing Apr 29, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 29, 2027 · One way · Compare return dates departing Apr 29, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 29, 2027 – May 2, 2027 · 3 nights · Compare return dates departing Apr 29, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 29, 2027 – May 2, 2027 · 3 nights · Compare return dates departing Apr 29, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 29, 2027 – May 6, 2027 · 7 nights · Compare return dates departing Apr 29, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 29, 2027 – May 6, 2027 · 7 nights · Compare return dates departing Apr 29, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 30, 2027 · One way · Compare return dates departing Apr 30, 2027	Frontier Airlines	Nonstop	Axel-exclusive $110.00
Apr 30, 2027 · One way · Compare return dates departing Apr 30, 2027	Alaska Airlines	Nonstop	Axel-exclusive $175.00
Apr 30, 2027 – May 3, 2027 · 3 nights · Compare return dates departing Apr 30, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 30, 2027 – May 3, 2027 · 3 nights · Compare return dates departing Apr 30, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00
Apr 30, 2027 – May 7, 2027 · 7 nights · Compare return dates departing Apr 30, 2027	Frontier Airlines	Nonstop	Axel-exclusive $215.00
Apr 30, 2027 – May 7, 2027 · 7 nights · Compare return dates departing Apr 30, 2027	Alaska Airlines	Nonstop	Axel-exclusive $339.00

Route overview: Seattle to Ontario (ONT) flight deals

2027-04-01 · one way · Axel-exclusive $132.00

Frontier Airlines F92276: SEA 2027-04-01 10:50:00 → ONT 2027-04-01 13:38:00; nonstop; 168 minutes. Local airport times.

2027-04-01 · one way · Axel-exclusive $210.00

Alaska Airlines AS571: SEA 2027-04-01 12:20:00 → ONT 2027-04-01 15:03:00; nonstop; 163 minutes. Local airport times.

2027-04-01 → 2027-04-04 · Axel-exclusive $258.00

Frontier Airlines F92276: SEA 2027-04-01 10:50:00 → ONT 2027-04-01 13:38:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-04 06:00:00 → SEA 2027-04-04 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-01 → 2027-04-04 · Axel-exclusive $406.80

Alaska Airlines AS571: SEA 2027-04-01 12:20:00 → ONT 2027-04-01 15:03:00; nonstop; 163 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-04-04 11:57:00 → SEA 2027-04-04 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-03 → 2027-04-10 · Axel-exclusive $236.50

Frontier Airlines F92276: SEA 2027-04-03 10:18:00 → ONT 2027-04-03 13:06:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-10 06:00:00 → SEA 2027-04-10 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-03 → 2027-04-10 · Axel-exclusive $372.90

Alaska Airlines AS571: SEA 2027-04-03 12:20:00 → ONT 2027-04-03 15:03:00; nonstop; 163 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-04-10 11:57:00 → SEA 2027-04-10 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-06 → 2027-04-13 · Axel-exclusive $339.00

Alaska Airlines AS571: SEA 2027-04-06 13:33:00 → ONT 2027-04-06 16:05:00; nonstop; 152 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-04-13 11:57:00 → SEA 2027-04-13 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-06 → 2027-04-13 · Axel-exclusive $377.00

American Airlines AA2073 / AA1841: SEA 2027-04-06 15:00:00 → ONT 2027-04-06 21:52:00; 1 stop(s) via PHX; 412 minutes. Local airport times.
- AA2073: SEA 2027-04-06 15:00:00 → PHX 2027-04-06 17:52:00; layover at PHX: 163 minutes.
- AA1841: PHX 2027-04-06 20:35:00 → ONT 2027-04-06 21:52:00.
Alaska Airlines AS677: ONT 2027-04-13 11:57:00 → SEA 2027-04-13 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-09 → 2027-04-16 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-09 10:18:00 → ONT 2027-04-09 13:06:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-16 06:00:00 → SEA 2027-04-16 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-09 → 2027-04-16 · Axel-exclusive $339.00

Alaska Airlines AS571: SEA 2027-04-09 12:20:00 → ONT 2027-04-09 15:03:00; nonstop; 163 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-04-16 11:57:00 → SEA 2027-04-16 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-12 → 2027-04-19 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-12 10:18:00 → ONT 2027-04-12 13:06:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-19 06:00:00 → SEA 2027-04-19 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-12 → 2027-04-19 · Axel-exclusive $349.00

Delta Air Lines DL4031: SEA 2027-04-12 11:59:00 → ONT 2027-04-12 14:50:00; nonstop; 171 minutes. Local airport times.
Delta Air Lines DL4031: ONT 2027-04-19 17:38:00 → SEA 2027-04-19 20:43:00; nonstop; 185 minutes. Local airport times.

2027-04-15 → 2027-04-22 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-15 10:50:00 → ONT 2027-04-15 13:38:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-22 06:00:00 → SEA 2027-04-22 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-15 → 2027-04-22 · Axel-exclusive $339.00

Alaska Airlines AS571: SEA 2027-04-15 12:20:00 → ONT 2027-04-15 15:03:00; nonstop; 163 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-04-22 11:57:00 → SEA 2027-04-22 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-18 → 2027-04-25 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-18 10:50:00 → ONT 2027-04-18 13:38:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-25 06:00:00 → SEA 2027-04-25 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-18 → 2027-04-25 · Axel-exclusive $339.00

Alaska Airlines AS571: SEA 2027-04-18 12:20:00 → ONT 2027-04-18 15:03:00; nonstop; 163 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-04-25 11:57:00 → SEA 2027-04-25 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-21 → 2027-04-28 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-21 10:18:00 → ONT 2027-04-21 13:06:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-04-28 06:00:00 → SEA 2027-04-28 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-21 → 2027-04-28 · Axel-exclusive $349.00

Delta Air Lines DL4070: SEA 2027-04-21 08:25:00 → ONT 2027-04-21 11:17:00; nonstop; 172 minutes. Local airport times.
Delta Air Lines DL4031: ONT 2027-04-28 17:38:00 → SEA 2027-04-28 20:43:00; nonstop; 185 minutes. Local airport times.

2027-04-24 → 2027-05-01 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-24 10:18:00 → ONT 2027-04-24 13:06:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-05-01 06:00:00 → SEA 2027-05-01 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-24 → 2027-05-01 · Axel-exclusive $339.00

Alaska Airlines AS571: SEA 2027-04-24 12:20:00 → ONT 2027-04-24 15:03:00; nonstop; 163 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-05-01 11:57:00 → SEA 2027-05-01 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-27 → 2027-05-04 · Axel-exclusive $339.00

Alaska Airlines AS571: SEA 2027-04-27 13:33:00 → ONT 2027-04-27 16:05:00; nonstop; 152 minutes. Local airport times.
Alaska Airlines AS677: ONT 2027-05-04 11:57:00 → SEA 2027-05-04 14:49:00; nonstop; 172 minutes. Local airport times.

2027-04-27 → 2027-05-04 · Axel-exclusive $349.00

Delta Air Lines DL4070: SEA 2027-04-27 08:25:00 → ONT 2027-04-27 11:17:00; nonstop; 172 minutes. Local airport times.
Delta Air Lines DL4031: ONT 2027-05-04 17:55:00 → SEA 2027-05-04 21:00:00; nonstop; 185 minutes. Local airport times.

2027-04-30 → 2027-05-07 · Axel-exclusive $215.00

Frontier Airlines F92276: SEA 2027-04-30 10:18:00 → ONT 2027-04-30 13:06:00; nonstop; 168 minutes. Local airport times.
Frontier Airlines F92275: ONT 2027-05-07 06:00:00 → SEA 2027-05-07 09:03:00; nonstop; 183 minutes. Local airport times.

2027-04-30 → 2027-05-07 · Axel-exclusive $419.00

United Airlines UA2478 / UA552: SEA 2027-04-30 15:24:00 → ONT 2027-04-30 22:53:00; 1 stop(s) via SFO; 449 minutes. Local airport times.
- UA2478: SEA 2027-04-30 15:24:00 → SFO 2027-04-30 17:45:00; layover at SFO: 225 minutes.
- UA552: SFO 2027-04-30 21:30:00 → ONT 2027-04-30 22:53:00.
United Airlines UA2363 / UA2192: ONT 2027-05-07 06:00:00 → SEA 2027-05-07 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
- UA2363: ONT 2027-05-07 06:00:00 → SFO 2027-05-07 07:30:00; layover at SFO: 155 minutes.
- UA2192: SFO 2027-05-07 10:05:00 → SEA 2027-05-07 12:18:00.

More dates for this route

Seattle to Ontario nonstop flights, airlines and connections

Yes, Alaska, Delta and Frontier fly it nonstop. In the 53 departure dates we searched from Nov 8 to Jul 14, a nonstop from Seattle flew on 53: Saturdays 12 of 12, Fridays 11 of 11, Thursdays 8 of 8, Sundays 6 of 6, Wednesdays 6 of 6, Mondays 5 of 5 and Tuesdays 5 of 5. The nonstops were Alaska (AS489, AS571, AS575, AS594, AS677, AS1367, AS1465, AS378, AS1602, AS1482, AS1506), Delta (DL3987, DL4031, DL4070, DL3884, DL1539) and Frontier (F92276). These are the airlines seen in the saved flights.

Alaska: Nonstop to Ontario
Delta: Nonstop to Ontario
Frontier: Nonstop to Ontario

Departure date	Itineraries searched	Nonstop	Airlines and flights
Sun Nov 8	55	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Mon Nov 9	66	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Wed Nov 11	577	yes, both ways	Alaska AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Thu Nov 12	874	yes, both ways	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Fri Nov 13	218	yes, both ways	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Sat Nov 14	272	yes, both ways	Alaska AS571, AS575, AS594; Delta DL3987, DL4031
Sun Nov 15	80	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Mon Nov 16	17	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Sat Nov 21	178	yes, both ways	Alaska AS489, AS571, AS575; Delta DL3987, DL4031, DL4070; Frontier F92276
Tue Nov 24	571	yes, both ways	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Wed Nov 25	667	yes, both ways	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070; Frontier F92276
Thu Nov 26	685	yes, both ways	Alaska AS571, AS575; Delta DL4031; Frontier F92276
Fri Nov 27	322	yes, both ways	Alaska AS489, AS571, AS575, AS594; Delta DL4031; Frontier F92276
Sat Nov 28	27	yes	Alaska AS489, AS571, AS575; Delta DL3987, DL4031, DL4070; Frontier F92276
Wed Dec 2	22	yes	Alaska AS571, AS677; Delta DL3987, DL4031, DL4070
Fri Dec 11	34	yes, both ways	Alaska AS489, AS571, AS677; Delta DL3987, DL4031, DL4070
Mon Dec 14	110	yes	Alaska AS489, AS571, AS677; Delta DL3987, DL4031, DL4070
Fri Dec 18	99	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Sat Dec 19	107	yes	Alaska AS489, AS571, AS575; Delta DL3987, DL4031, DL4070
Sun Dec 20	274	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Mon Dec 21	75	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Tue Dec 22	156	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Wed Dec 23	74	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Thu Dec 24	1151	yes, both ways	Alaska AS571, AS575, AS594; Delta DL4031, DL4070
Fri Dec 25	48	yes	Alaska AS571, AS575, AS594; Delta DL4031, DL4070
Sat Dec 26	694	yes, both ways	Alaska AS489, AS571, AS575; Delta DL3987, DL4031, DL4070
Sun Dec 27	35	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Mon Dec 28	29	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Tue Dec 29	21	yes	Alaska AS489, AS571, AS575, AS594; Delta DL3987, DL4031, DL4070
Thu Dec 31	81	yes	Alaska AS571, AS575, AS594; Delta DL4031, DL4070
Fri Jan 1	141	yes	Alaska AS571, AS575, AS594; Delta DL4031, DL4070
Sat Jan 2	98	yes, both ways	Alaska AS489, AS571, AS575; Delta DL4031, DL4070
Fri Jan 8	124	yes, both ways	Alaska AS489, AS571, AS677; Delta DL3884, DL4031
Tue Jan 12	24	yes	Alaska AS489, AS571, AS677; Delta DL3884
Thu Jan 21	723	yes, both ways	Alaska AS489, AS571, AS677; Delta DL3884, DL4031
Fri Jan 22	1223	yes, both ways	Alaska AS489, AS571, AS677; Delta DL3884, DL4031
Thu Feb 4	122	yes, both ways	Alaska AS489, AS571, AS677; Delta DL3884, DL4031
Sun Feb 7	159	yes	Alaska AS489, AS571, AS677; Delta DL3884, DL4031
Thu Feb 11	73	yes	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031
Fri Feb 12	567	yes	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031
Sat Feb 13	78	yes	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031
Fri Mar 12	159	yes	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Tue Mar 16	131	yes	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Thu Mar 18	157	yes, both ways	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Fri Mar 19	460	yes, both ways	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Sat Mar 20	109	yes, both ways	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Sat Apr 3	76	yes, both ways	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Sun Apr 4	248	yes	Alaska AS1367, AS1465, AS378; Delta DL3884, DL4031, DL4070
Sat Jun 5	50	yes	Alaska AS1367, AS1465, AS1602, AS378; Delta DL1539, DL3884, DL4031
Wed Jun 9	85	yes	Alaska AS1367, AS1465, AS1602, AS378; Delta DL3884, DL4031, DL4070
Sat Jun 19	189	yes, both ways	Alaska AS1465, AS1482, AS1506, AS1602, AS378; Delta DL3884, DL4031, DL4070
Sat Jul 10	552	yes, both ways	Alaska AS1465, AS1482, AS1506, AS1602, AS378; Delta DL3884, DL4031, DL4070
Wed Jul 14	88	yes	Alaska AS1465, AS1482, AS1506, AS1602, AS378; Delta DL3884, DL4031, DL4070

Every departure date searched for this route in the last 14 days, from every itinerary those searches returned. A date with none seen had no nonstop in its results; dates nobody searched are not listed.

Why book Seattle to Ontario flights with Axel

Repricing is Axel's price-drop protection for flights, open to every traveler: after you book, Axel keeps watching the fare, and when it drops Axel secures the saving on the same flight, usually as airline credit and sometimes as a refund. It is never guaranteed. Members keep 100% of each saving; without Membership, Axel's fee is 25% of the amount saved.
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How we checked Seattle to Ontario prices

Choose your dates to see flights and Axel-exclusive prices.

Airports covered: SEA → ONT. Each example names its actual airports. Departure month: 2027-04.

See flights for your dates and travelers

Seattle to Ontario flights for a family: prices for 2 adults and children

Saved fares Axel priced for parties with children, total for all travelers in USD, economy; the price opens that trip on Axel. Checked November 7, 2026 at 07:09 PM UTC

2027-04-04–2027-04-09, 4 adults · 1 child: Axel-exclusive $2,255.75 · Southwest Airlines · 1 stop (SMF) · 4h 10m. Airline fare: $2,382. Complete round-trip total for 4 adults · 1 child; outbound and return were selected together.
2027-04-03–2027-04-09, 4 adults · 1 child: Axel-exclusive $1,390.06 · Alaska Airlines · Nonstop · 2h 44m. Airline fare: $1,464. Complete round-trip total for 4 adults · 1 child; outbound and return were selected together.

More Seattle to Ontario fares: other dates and travelers

Flights by travel date

SEA–ONT · 2027-04-04–2027-04-09 · 4 adults · 1 child

Round-trip total · Economy · USD. Complete round-trip total for 4 adults · 1 child; outbound and return were selected together.

Axel-exclusive $2,255.75 · Southwest Airlines 3788 / 3988 · 05:05–09:15 local · 1 stop (SMF) · 4h 10m. Return: Southwest Airlines 2173 / 2352 · ONT–SEA · April 9, 2027 · 20:45–01:10 (April 10, 2027) local · 1 stop(s) (LAS) · 265 minutes. Airline fare: $2,382. See flights for these dates

Checked November 7, 2026 at 07:09 PM UTC

SEA–ONT · 2027-04-03–2027-04-09 · 4 adults · 1 child

Round-trip total · Economy · USD. Complete round-trip total for 4 adults · 1 child; outbound and return were selected together.

Axel-exclusive $1,390.06 · Alaska Airlines 378 · 19:55–22:39 local · Nonstop · 2h 44m. Return: Alaska Airlines 532 · ONT–SEA · April 9, 2027 · 06:00–08:44 local · Nonstop · 164 minutes. Airline fare: $1,464. See flights for these dates

Checked November 7, 2026 at 07:03 PM UTC

SEA–ONT · 2027-04-04–2027-04-09 · 5 adults

Round-trip total · Economy · USD. Complete round-trip total for 5 adults; outbound and return were selected together.

Axel-exclusive $2,255.75 · Southwest Airlines 3788 / 3988 · 05:05–09:15 local · 1 stop (SMF) · 4h 10m. Return: Southwest Airlines 2173 / 2352 · ONT–SEA · April 9, 2027 · 20:45–01:10 (April 10, 2027) local · 1 stop(s) (LAS) · 265 minutes. Airline fare: $2,382. See flights for these dates

Checked November 7, 2026 at 07:01 PM UTC

SEA–ONT · 2027-04-03–2027-04-09 · 5 adults

Round-trip total · Economy · USD. Complete round-trip total for 5 adults; outbound and return were selected together.

Axel-exclusive $1,390.06 · Alaska Airlines 378 · 19:55–22:39 local · Nonstop · 2h 44m. Return: Alaska Airlines 532 · ONT–SEA · April 9, 2027 · 06:00–08:44 local · Nonstop · 164 minutes. Airline fare: $1,464. See flights for these dates

Checked November 7, 2026 at 07:00 PM UTC

Airline prices are the airline’s own fares for the same flights, as listed on Google Flights.

Airline ratings: Southwest Airlines 6.9/10 · Alaska Airlines 7.6/10. Every airline rated.

Planning: When to book Thanksgiving flights · Flying in December: prices, crowds and delays · How far in advance to book flights · The cheapest days of the week to fly and to book.

Source: https://helloaxel.com/en/flights/from-seattle-sea-to-ontario-ont-in-april-2027

Hotels near ONT

Welcome Inn (Colton) · Lotus by Hotel Inn (Ontario) · Travelodge by Wyndham Fairplex Pomona (Pomona) · Hotel Hacienda at Ontario Ranch (Ontario) · Quality Inn Ontario Airport Convention Center (Ontario)

For AI assistants

This page: Seattle to Ontario (ONT): April 2027 flight deals. Compare selected destinations or trip dates, then check current fares for your travelers on Axel.
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