Travel with Axel,
get the best price.

Seattle → Ontario

Nov 21, 2026 · return Dec 5, 2026

SEA → ONT1 adulteconomyRound trip

10 flight options · 6 airlines

Nonstop flights

Sat, Nov 21 – Sat, Dec 5

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

Sat, Nov 21 – Sat, Dec 5

Alaska Airlines
12:20 pmSEA
2h 43m
Nonstop
3:03 pmONT
Alaska Airlines
4:09 pmONT
2h 47m
Nonstop
6:56 pmSEA

Round-trip total · 1 adult · Taxes included

Sat, Nov 21 – Sat, Dec 5

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

Sat, Nov 21 – Sat, Dec 5

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

Sat, Nov 21 – Sat, Dec 5

Southwest Airlines
8:05 amSEA
4h 35m
SJC · 1h
12:40 pmONT
Southwest Airlines
4:05 pmONT
5h 35m
OAK · 1h 50m
9:40 pmSEA

Round-trip total · 1 adult · Taxes included

Sat, Nov 21 – Sat, Dec 5

American Airlines
3:00 pmSEA
6h 52m
PHX · 2h 43m
9:52 pmONT
Southwest Airlines
4:05 pmONT
5h 35m
OAK · 1h 50m
9:40 pmSEA

Round-trip total · 1 adult · Taxes included

Sat, Nov 21 – Sat, Dec 5

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

Sat, Nov 21 – Sat, Dec 5

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

Sat, Nov 21 – Sat, Dec 5

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

Sat, Nov 21 – Sat, Dec 5

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.

No account needed to see prices.

Already have an account? Log in

Why book with Axel
  • A real airline bookingThe booking is in the airline’s own system under your name. After you book, Frontier Airlines emails you its confirmation code and e-ticket, usually within 15 minutes and occasionally up to a couple of hours while the booking is processed.
  • Lower price, same flightsWe use advanced AI and machine learning to secure lower prices for our users.
  • Not satisfied? Full refund.If you are unhappy with the experience for any reason, or simply change your mind, cancel within 24 hours of booking (departure 7+ days away) and we refund you in full. We stand by our product. Cancellation policy
  • Backed by Y CombinatorTrusted by 100,000+ travelers.

Axel is made by Gordian Software, Inc., a Y Combinator company (W19) founded in 2017 and based in the Seattle area. The company is led by CEO Stephen Grabowski, formerly of Skyscanner. How Axel works · About

More dates

All dates for this routeNov 5, 2026 → Nov 8, 2026Nov 14, 2026 → Nov 21, 2026Nov 24, 2026 → Nov 29, 2026Dec 5, 2026 → Dec 12, 2026Dec 17, 2026 → Dec 20, 2026Dec 26, 2026 → Jan 2, 2027Jan 5, 2027 · One wayJan 16, 2027 → Jan 23, 2027Feb 5, 2027 → Feb 8, 2027Apr 3, 2027 → Apr 10, 2027Jun 26, 2027 → Jul 3, 2027Sep 17, 2027 → Sep 20, 2027
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.

Exact travel datesAirlineFlightsTotal pricePrice issued (UTC)
2026-11-21 → 2026-12-05Frontier AirlinesF92276 / F92275$193.882026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Alaska AirlinesAS571 / AS571$327.832026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Delta Air LinesDL4031 / DL4070$339.582026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Southwest AirlinesWN3105 + WN1383 / WN3313 + WN4608$374.832026-10-29T01:16:03Z
2026-11-21 → 2026-12-05American Airlines / Southwest AirlinesAA2073 + AA1841 / WN3313 + WN4608$399.132026-10-29T01:16:03Z
2026-11-21 → 2026-12-05United AirlinesUA2478 + UA552 / UA2363 + UA2192$421.832026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Alaska AirlinesAS489 / AS571$327.832026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Frontier AirlinesF92408 + F91923 / F92275$234.382026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Alaska AirlinesAS3087 + AS3380 / AS571$365.632026-10-29T01:16:03Z
2026-11-21 → 2026-12-05Delta Air LinesDL1016 + DL3879 / DL4070$377.382026-10-29T01:16:03Z

2026-11-21 → 2026-12-05 · $193.88

  • Frontier Airlines F92276: SEA 2026-11-21 10:50:00 → ONT 2026-11-21 13:38:00; nonstop; 168 minutes. Local airport times.
  • Frontier Airlines F92275: ONT 2026-12-05 06:00:00 → SEA 2026-12-05 09:03:00; nonstop; 183 minutes. Local airport times.

2026-11-21 → 2026-12-05 · $327.83

  • Alaska Airlines AS571: SEA 2026-11-21 12:20:00 → ONT 2026-11-21 15:03:00; nonstop; 163 minutes. Local airport times.
  • Alaska Airlines AS571: ONT 2026-12-05 16:09:00 → SEA 2026-12-05 18:56:00; nonstop; 167 minutes. Local airport times.

2026-11-21 → 2026-12-05 · $339.58

  • Delta Air Lines DL4031: SEA 2026-11-21 11:59:00 → ONT 2026-11-21 14:50:00; nonstop; 171 minutes. Local airport times.
  • Delta Air Lines DL4070: ONT 2026-12-05 11:57:00 → SEA 2026-12-05 14:56:00; nonstop; 179 minutes. Local airport times.

2026-11-21 → 2026-12-05 · $374.83

  • Southwest Airlines WN3105 / WN1383: SEA 2026-11-21 08:05:00 → ONT 2026-11-21 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-11-21 08:05:00 → SJC 2026-11-21 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-11-21 11:20:00 → ONT 2026-11-21 12:40:00.
  • Southwest Airlines WN3313 / WN4608: ONT 2026-12-05 16:05:00 → SEA 2026-12-05 21:40:00; 1 stop(s) via OAK; 335 minutes. Local airport times.
    • WN3313: ONT 2026-12-05 16:05:00 → OAK 2026-12-05 17:30:00; layover at OAK: 110 minutes.
    • WN4608: OAK 2026-12-05 19:20:00 → SEA 2026-12-05 21:40:00.

2026-11-21 → 2026-12-05 · $399.13

  • American Airlines AA2073 / AA1841: SEA 2026-11-21 15:00:00 → ONT 2026-11-21 21:52:00; 1 stop(s) via PHX; 412 minutes. Local airport times.
    • AA2073: SEA 2026-11-21 15:00:00 → PHX 2026-11-21 18:52:00; layover at PHX: 163 minutes.
    • AA1841: PHX 2026-11-21 21:35:00 → ONT 2026-11-21 21:52:00.
  • Southwest Airlines WN3313 / WN4608: ONT 2026-12-05 16:05:00 → SEA 2026-12-05 21:40:00; 1 stop(s) via OAK; 335 minutes. Local airport times.
    • WN3313: ONT 2026-12-05 16:05:00 → OAK 2026-12-05 17:30:00; layover at OAK: 110 minutes.
    • WN4608: OAK 2026-12-05 19:20:00 → SEA 2026-12-05 21:40:00.

2026-11-21 → 2026-12-05 · $421.83

  • United Airlines UA2478 / UA552: SEA 2026-11-21 15:24:00 → ONT 2026-11-21 22:53:00; 1 stop(s) via SFO; 449 minutes. Local airport times.
    • UA2478: SEA 2026-11-21 15:24:00 → SFO 2026-11-21 17:45:00; layover at SFO: 225 minutes.
    • UA552: SFO 2026-11-21 21:30:00 → ONT 2026-11-21 22:53:00.
  • United Airlines UA2363 / UA2192: ONT 2026-12-05 06:00:00 → SEA 2026-12-05 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
    • UA2363: ONT 2026-12-05 06:00:00 → SFO 2026-12-05 07:30:00; layover at SFO: 155 minutes.
    • UA2192: SFO 2026-12-05 10:05:00 → SEA 2026-12-05 12:18:00.

2026-11-21 → 2026-12-05 · $327.83

  • Alaska Airlines AS489: SEA 2026-11-21 21:23:00 → ONT 2026-11-21 23:59:00; nonstop; 156 minutes. Local airport times.
  • Alaska Airlines AS571: ONT 2026-12-05 16:09:00 → SEA 2026-12-05 18:56:00; nonstop; 167 minutes. Local airport times.

2026-11-21 → 2026-12-05 · $234.38

  • Frontier Airlines F92408 / F91923: SEA 2026-11-21 11:53:00 → ONT 2026-11-21 18:31:00; 1 stop(s) via LAS; 398 minutes. Local airport times.
    • F92408: SEA 2026-11-21 11:53:00 → LAS 2026-11-21 14:32:00; layover at LAS: 173 minutes.
    • F91923: LAS 2026-11-21 17:25:00 → ONT 2026-11-21 18:31:00.
  • Frontier Airlines F92275: ONT 2026-12-05 06:00:00 → SEA 2026-12-05 09:03:00; nonstop; 183 minutes. Local airport times.

2026-11-21 → 2026-12-05 · $365.63

  • Alaska Airlines AS3087 / AS3380: SEA 2026-11-21 09:50:00 → ONT 2026-11-21 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
    • AS3087: SEA 2026-11-21 09:50:00 → BOI 2026-11-21 12:21:00; layover at BOI: 199 minutes.
    • AS3380: BOI 2026-11-21 15:40:00 → ONT 2026-11-21 16:56:00.
  • Alaska Airlines AS571: ONT 2026-12-05 16:09:00 → SEA 2026-12-05 18:56:00; nonstop; 167 minutes. Local airport times.

2026-11-21 → 2026-12-05 · $377.38

  • Delta Air Lines DL1016 / DL3879: SEA 2026-11-21 09:18:00 → ONT 2026-11-21 16:22:00; 1 stop(s) via SLC; 424 minutes. Local airport times.
    • DL1016: SEA 2026-11-21 09:18:00 → SLC 2026-11-21 12:31:00; layover at SLC: 178 minutes.
    • DL3879: SLC 2026-11-21 15:29:00 → ONT 2026-11-21 16:22:00.
  • Delta Air Lines DL4070: ONT 2026-12-05 11:57:00 → SEA 2026-12-05 14:56:00; nonstop; 179 minutes. Local airport times.

More dates for this route