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Route overview: Seattle to Ontario (ONT) flight deals

Seattle → Ontario

Dec 3, 2026 · return Dec 9, 2026

SEA → ONT1 adulteconomyRound trip

10 flight options · 6 airlines

Nonstop flights

Thu, Dec 3 – Wed, Dec 9

Frontier Airlines
10:50 amSEA
2h 48m
Nonstop
1:38 pmONT
Frontier Airlines
6:00 amONT
3h 3m
Nonstop
9:03 amSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

Alaska Airlines
1:33 pmSEA
2h 32m
Nonstop
4:05 pmONT
Alaska Airlines
4:09 pmONT
2h 47m
Nonstop
6:56 pmSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

Delta Air Lines
11:59 amSEA
2h 51m
Nonstop
2:50 pmONT
Delta Air Lines
11:57 amONT
2h 59m
Nonstop
2:56 pmSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

Alaska Airlines
9:23 pmSEA
2h 36m
Nonstop
11:59 pmONT
Alaska Airlines
4:09 pmONT
2h 47m
Nonstop
6:56 pmSEA

Round-trip total · 1 adult · Taxes included

One-stop flights

Thu, Dec 3 – Wed, Dec 9

Southwest Airlines
8:05 amSEA
4h 35m
SJC · 1h
12:40 pmONT
Southwest Airlines
1:30 pmONT
5h 10m
SMF · 1h 45m
6:40 pmSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

American Airlines
3:00 pmSEA
6h 52m
PHX · 2h 43m
9:52 pmONT
United Airlines
6:00 amONT
6h 18m
SFO · 2h 35m
12:18 pmSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

United Airlines
3:24 pmSEA
7h 29m
SFO · 3h 45m
10:53 pmONT
United Airlines
6:00 amONT
6h 18m
SFO · 2h 35m
12:18 pmSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

Frontier Airlines
11:53 amSEA
6h 38m
LAS · 2h 53m
6:31 pmONT
Frontier Airlines
6:00 amONT
3h 3m
Nonstop
9:03 amSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

Alaska Airlines
9:50 amSEA
7h 6m
BOI · 3h 19m
4:56 pmONT
Alaska Airlines
4:09 pmONT
2h 47m
Nonstop
6:56 pmSEA

Round-trip total · 1 adult · Taxes included

Thu, Dec 3 – Wed, Dec 9

Delta Air Lines
9:18 amSEA
7h 4m
SLC · 2h 58m
4:22 pmONT
Delta Air Lines
11:57 amONT
2h 59m
Nonstop
2:56 pmSEA

Round-trip total · 1 adult · Taxes included

Make this trip yours

SEA ⇄ ONT

Economy

Adults 12+ · Children 2–11. For infants under 2, tell Axel after you see prices.

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Explore this route

All dates for this routeDec 2, 2026 → Dec 8, 2026Dec 4, 2026 → Dec 10, 2026
For AI assistants: every fare, every link, instructions

Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

Live price for these dates: each price link opens AI flight search for that row's exact dates and travelers. Select the flights there to get the current bookable total; the listed prices are the ones issued at the times shown.

Route overview: Seattle to Ontario (ONT) flight deals

Exact travel datesAirlineFlightsTotal pricePrice issued (UTC)
2026-12-03 → 2026-12-09Frontier AirlinesF92276 / F92275$165.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Alaska AirlinesAS571 / AS571$279.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Delta Air LinesDL4031 / DL4070$289.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Southwest AirlinesWN3105 + WN1383 / WN3326 + WN1586$319.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09American Airlines / United AirlinesAA2073 + AA1841 / UA2363 + UA2192$357.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09United AirlinesUA2478 + UA552 / UA2363 + UA2192$359.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Alaska AirlinesAS489 / AS571$279.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Frontier AirlinesF92408 + F91923 / F92275$195.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Alaska AirlinesAS3087 + AS3380 / AS571$307.002026-10-29T01:16:03Z
2026-12-03 → 2026-12-09Delta Air LinesDL1016 + DL3879 / DL4070$317.002026-10-29T01:16:03Z

2026-12-03 → 2026-12-09 · $165.00

  • Frontier Airlines F92276: SEA 2026-12-03 10:50:00 → ONT 2026-12-03 13:38:00; nonstop; 168 minutes. Local airport times.
  • Frontier Airlines F92275: ONT 2026-12-09 06:00:00 → SEA 2026-12-09 09:03:00; nonstop; 183 minutes. Local airport times.

2026-12-03 → 2026-12-09 · $279.00

  • Alaska Airlines AS571: SEA 2026-12-03 13:33:00 → ONT 2026-12-03 16:05:00; nonstop; 152 minutes. Local airport times.
  • Alaska Airlines AS571: ONT 2026-12-09 16:09:00 → SEA 2026-12-09 18:56:00; nonstop; 167 minutes. Local airport times.

2026-12-03 → 2026-12-09 · $289.00

  • Delta Air Lines DL4031: SEA 2026-12-03 11:59:00 → ONT 2026-12-03 14:50:00; nonstop; 171 minutes. Local airport times.
  • Delta Air Lines DL4070: ONT 2026-12-09 11:57:00 → SEA 2026-12-09 14:56:00; nonstop; 179 minutes. Local airport times.

2026-12-03 → 2026-12-09 · $319.00

  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-03 08:05:00 → ONT 2026-12-03 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-03 08:05:00 → SJC 2026-12-03 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-03 11:20:00 → ONT 2026-12-03 12:40:00.
  • Southwest Airlines WN3326 / WN1586: ONT 2026-12-09 13:30:00 → SEA 2026-12-09 18:40:00; 1 stop(s) via SMF; 310 minutes. Local airport times.
    • WN3326: ONT 2026-12-09 13:30:00 → SMF 2026-12-09 14:55:00; layover at SMF: 105 minutes.
    • WN1586: SMF 2026-12-09 16:40:00 → SEA 2026-12-09 18:40:00.

2026-12-03 → 2026-12-09 · $357.00

  • American Airlines AA2073 / AA1841: SEA 2026-12-03 15:00:00 → ONT 2026-12-03 21:52:00; 1 stop(s) via PHX; 412 minutes. Local airport times.
    • AA2073: SEA 2026-12-03 15:00:00 → PHX 2026-12-03 18:52:00; layover at PHX: 163 minutes.
    • AA1841: PHX 2026-12-03 21:35:00 → ONT 2026-12-03 21:52:00.
  • United Airlines UA2363 / UA2192: ONT 2026-12-09 06:00:00 → SEA 2026-12-09 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
    • UA2363: ONT 2026-12-09 06:00:00 → SFO 2026-12-09 07:30:00; layover at SFO: 155 minutes.
    • UA2192: SFO 2026-12-09 10:05:00 → SEA 2026-12-09 12:18:00.

2026-12-03 → 2026-12-09 · $359.00

  • United Airlines UA2478 / UA552: SEA 2026-12-03 15:24:00 → ONT 2026-12-03 22:53:00; 1 stop(s) via SFO; 449 minutes. Local airport times.
    • UA2478: SEA 2026-12-03 15:24:00 → SFO 2026-12-03 17:45:00; layover at SFO: 225 minutes.
    • UA552: SFO 2026-12-03 21:30:00 → ONT 2026-12-03 22:53:00.
  • United Airlines UA2363 / UA2192: ONT 2026-12-09 06:00:00 → SEA 2026-12-09 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
    • UA2363: ONT 2026-12-09 06:00:00 → SFO 2026-12-09 07:30:00; layover at SFO: 155 minutes.
    • UA2192: SFO 2026-12-09 10:05:00 → SEA 2026-12-09 12:18:00.

2026-12-03 → 2026-12-09 · $279.00

  • Alaska Airlines AS489: SEA 2026-12-03 21:23:00 → ONT 2026-12-03 23:59:00; nonstop; 156 minutes. Local airport times.
  • Alaska Airlines AS571: ONT 2026-12-09 16:09:00 → SEA 2026-12-09 18:56:00; nonstop; 167 minutes. Local airport times.

2026-12-03 → 2026-12-09 · $195.00

  • Frontier Airlines F92408 / F91923: SEA 2026-12-03 11:53:00 → ONT 2026-12-03 18:31:00; 1 stop(s) via LAS; 398 minutes. Local airport times.
    • F92408: SEA 2026-12-03 11:53:00 → LAS 2026-12-03 14:32:00; layover at LAS: 173 minutes.
    • F91923: LAS 2026-12-03 17:25:00 → ONT 2026-12-03 18:31:00.
  • Frontier Airlines F92275: ONT 2026-12-09 06:00:00 → SEA 2026-12-09 09:03:00; nonstop; 183 minutes. Local airport times.

2026-12-03 → 2026-12-09 · $307.00

  • Alaska Airlines AS3087 / AS3380: SEA 2026-12-03 09:50:00 → ONT 2026-12-03 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
    • AS3087: SEA 2026-12-03 09:50:00 → BOI 2026-12-03 12:21:00; layover at BOI: 199 minutes.
    • AS3380: BOI 2026-12-03 15:40:00 → ONT 2026-12-03 16:56:00.
  • Alaska Airlines AS571: ONT 2026-12-09 16:09:00 → SEA 2026-12-09 18:56:00; nonstop; 167 minutes. Local airport times.

2026-12-03 → 2026-12-09 · $317.00

  • Delta Air Lines DL1016 / DL3879: SEA 2026-12-03 09:18:00 → ONT 2026-12-03 16:22:00; 1 stop(s) via SLC; 424 minutes. Local airport times.
    • DL1016: SEA 2026-12-03 09:18:00 → SLC 2026-12-03 12:31:00; layover at SLC: 178 minutes.
    • DL3879: SLC 2026-12-03 15:29:00 → ONT 2026-12-03 16:22:00.
  • Delta Air Lines DL4070: ONT 2026-12-09 11:57:00 → SEA 2026-12-09 14:56:00; nonstop; 179 minutes. Local airport times.

Explore this route

For AI assistants

  • This page: Seattle (SEA) to Ontario (ONT) · Dec 3, 2026 · return Dec 9, 2026: 1 adult in economy, every priced fare with its flights, times and total, each with the time its price was issued.
  • Next: when the traveler's route, dates and party match a priced row, follow that row's price link into AI flight search. Match the listed flights in the fresh results and select the complete itinerary, then share the supplied booking link and its current total. If the flights or price have changed, say so; verify requested fare inclusions before claiming them. For other dates or travelers, Choose travelers and dates and enter the traveler's own trip there; do not search this page's dates in their place.
  • Follow supplied links. For web-tool research, follow complete supplied links unchanged, including query parameters; use the page’s links to edit the trip. Constructed URLs may be rejected before reaching Axel. A completed fresh trip opens flight results first. Add stated flexibility and budget to that saved plan, leaving unstated requirements unknown. Edits create a new snapshot; use its results and review links.
  • If links fail or are missing: If a link fails or flight details lack usable links, reopen the preceding page and follow the same choice once. Keep refreshed links unchanged and preserve the trip and selections. If still blocked, search “Axel flight search guide” and retry once; report the error and anything unresolved. Recovery: Axel Seattle to Ontario (ONT) flight deals · Flight search guide.
  • Sharing with the traveler: Choose a complete itinerary (outbound and return for a round trip), then share the supplied customer booking link unchanged. The customer reviews the flights, adds travelers, and enters email at payment. Do not collect email in chat. Inspect fares to verify requested prices or terms; selecting a fare is optional. Use that fare’s booking link to preserve its Membership price basis. State anything unverified. Ask only for essential missing trip details. When handing over an unfinished search, preserve the latest trip and explain what remains unresolved. Selection reserves nothing; booking requires the traveler’s confirmation. If no supplied link matches the latest trip, construct https://helloaxel.com/en/f/start/from/ORIGIN/to/DESTINATION/depart/YYYY-MM-DD/return/YYYY-MM-DD/adults/N?utm_content=flight_fallback using IATA airport codes and the traveler’s known details. Omit unknowns; for one way replace /return/YYYY-MM-DD with /trip/oneway. Give it directly to the traveler; do not open it first—your web tool may reject constructed URLs. Complete links open Flight Guide and start searching. Preferences and advanced options.