Travel with Axel,
get the best price.

Ontario → Seattle

Dec 21, 2026 · return Dec 27, 2026

ONT → SEA1 adulteconomyRound trip

10 flight options · 5 airlines

Nonstop flights

Mon, Dec 21 – Sun, Dec 27

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

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

Alaska Airlines
6:00 amONT
2h 51m
Nonstop
8:51 amSEA
Alaska Airlines
12:20 pmSEA
2h 43m
Nonstop
3:03 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

Delta Air Lines
5:56 pmONT
3h 1m
Nonstop
8:57 pmSEA
Delta Air Lines
11:59 amSEA
2h 51m
Nonstop
2:50 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

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

Round-trip total · 1 adult · Taxes included

One-stop flights

Mon, Dec 21 – Sun, Dec 27

Southwest Airlines
5:00 pmONT
5h 20m
LAS · 1h 25m
10:20 pmSEA
Southwest Airlines
8:05 amSEA
4h 35m
SJC · 1h
12:40 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

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

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

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

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

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

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

Alaska Airlines
5:36 pmONT
4h 52m
BOI · 1h 6m
10:28 pmSEA
Alaska Airlines
12:20 pmSEA
2h 43m
Nonstop
3:03 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Sun, Dec 27

Delta Air Lines
5:38 pmONT
3h 5m
Nonstop
8:43 pmSEA
Delta Air Lines
9:18 amSEA
7h 4m
SLC · 2h 58m
4:22 pmONT

Round-trip total · 1 adult · Taxes included

Make this trip yours

ONT ⇄ SEA

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 20, 2026 → Nov 23, 2026Nov 27, 2026 → Dec 4, 2026Nov 20, 2026 · One way
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)
2026-12-21 → 2026-12-27Frontier AirlinesF92275 / F92276$195.762026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Alaska AirlinesAS607 / AS571$351.002026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Delta Air LinesDL4031 / DL4031$364.502026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Southwest AirlinesWN1053 + WN4083 / WN3105 + WN1383$364.502026-10-29T01:52:37Z
2026-12-21 → 2026-12-27United AirlinesUA2363 + UA2192 / UA2478 + UA552$391.502026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Alaska AirlinesAS571 / AS571$351.002026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Southwest AirlinesWN3313 + WN4608 / WN3105 + WN1383$364.502026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Southwest AirlinesWN3326 + WN1586 / WN3105 + WN1383$364.502026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Alaska AirlinesAS3380 + AS2016 / AS571$364.502026-10-29T01:52:37Z
2026-12-21 → 2026-12-27Delta Air LinesDL4031 / DL1016 + DL3879$378.002026-10-29T01:52:37Z

2026-12-21 → 2026-12-27 · $195.76

  • Frontier Airlines F92275: ONT 2026-12-21 06:00:00 → SEA 2026-12-21 09:03:00; nonstop; 183 minutes. Local airport times.
  • Frontier Airlines F92276: SEA 2026-12-27 10:50:00 → ONT 2026-12-27 13:38:00; nonstop; 168 minutes. Local airport times.

2026-12-21 → 2026-12-27 · $351.00

  • Alaska Airlines AS607: ONT 2026-12-21 06:00:00 → SEA 2026-12-21 08:51:00; nonstop; 171 minutes. Local airport times.
  • Alaska Airlines AS571: SEA 2026-12-27 12:20:00 → ONT 2026-12-27 15:03:00; nonstop; 163 minutes. Local airport times.

2026-12-21 → 2026-12-27 · $364.50

  • Delta Air Lines DL4031: ONT 2026-12-21 17:56:00 → SEA 2026-12-21 20:57:00; nonstop; 181 minutes. Local airport times.
  • Delta Air Lines DL4031: SEA 2026-12-27 11:59:00 → ONT 2026-12-27 14:50:00; nonstop; 171 minutes. Local airport times.

2026-12-21 → 2026-12-27 · $364.50

  • Southwest Airlines WN1053 / WN4083: ONT 2026-12-21 17:00:00 → SEA 2026-12-21 22:20:00; 1 stop(s) via LAS; 320 minutes. Local airport times.
    • WN1053: ONT 2026-12-21 17:00:00 → LAS 2026-12-21 18:05:00; layover at LAS: 85 minutes.
    • WN4083: LAS 2026-12-21 19:30:00 → SEA 2026-12-21 22:20:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-27 08:05:00 → ONT 2026-12-27 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-27 08:05:00 → SJC 2026-12-27 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-27 11:20:00 → ONT 2026-12-27 12:40:00.

2026-12-21 → 2026-12-27 · $391.50

  • United Airlines UA2363 / UA2192: ONT 2026-12-21 06:00:00 → SEA 2026-12-21 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
    • UA2363: ONT 2026-12-21 06:00:00 → SFO 2026-12-21 07:30:00; layover at SFO: 155 minutes.
    • UA2192: SFO 2026-12-21 10:05:00 → SEA 2026-12-21 12:18:00.
  • United Airlines UA2478 / UA552: SEA 2026-12-27 15:24:00 → ONT 2026-12-27 22:53:00; 1 stop(s) via SFO; 449 minutes. Local airport times.
    • UA2478: SEA 2026-12-27 15:24:00 → SFO 2026-12-27 17:45:00; layover at SFO: 225 minutes.
    • UA552: SFO 2026-12-27 21:30:00 → ONT 2026-12-27 22:53:00.

2026-12-21 → 2026-12-27 · $351.00

  • Alaska Airlines AS571: ONT 2026-12-21 16:09:00 → SEA 2026-12-21 18:56:00; nonstop; 167 minutes. Local airport times.
  • Alaska Airlines AS571: SEA 2026-12-27 12:20:00 → ONT 2026-12-27 15:03:00; nonstop; 163 minutes. Local airport times.

2026-12-21 → 2026-12-27 · $364.50

  • Southwest Airlines WN3313 / WN4608: ONT 2026-12-21 16:05:00 → SEA 2026-12-21 21:40:00; 1 stop(s) via OAK; 335 minutes. Local airport times.
    • WN3313: ONT 2026-12-21 16:05:00 → OAK 2026-12-21 17:30:00; layover at OAK: 110 minutes.
    • WN4608: OAK 2026-12-21 19:20:00 → SEA 2026-12-21 21:40:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-27 08:05:00 → ONT 2026-12-27 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-27 08:05:00 → SJC 2026-12-27 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-27 11:20:00 → ONT 2026-12-27 12:40:00.

2026-12-21 → 2026-12-27 · $364.50

  • Southwest Airlines WN3326 / WN1586: ONT 2026-12-21 13:30:00 → SEA 2026-12-21 18:40:00; 1 stop(s) via SMF; 310 minutes. Local airport times.
    • WN3326: ONT 2026-12-21 13:30:00 → SMF 2026-12-21 14:55:00; layover at SMF: 105 minutes.
    • WN1586: SMF 2026-12-21 16:40:00 → SEA 2026-12-21 18:40:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-27 08:05:00 → ONT 2026-12-27 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-27 08:05:00 → SJC 2026-12-27 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-27 11:20:00 → ONT 2026-12-27 12:40:00.

2026-12-21 → 2026-12-27 · $364.50

  • Alaska Airlines AS3380 / AS2016: ONT 2026-12-21 17:36:00 → SEA 2026-12-21 22:28:00; 1 stop(s) via BOI; 292 minutes. Local airport times.
    • AS3380: ONT 2026-12-21 17:36:00 → BOI 2026-12-21 20:41:00; layover at BOI: 66 minutes.
    • AS2016: BOI 2026-12-21 21:47:00 → SEA 2026-12-21 22:28:00.
  • Alaska Airlines AS571: SEA 2026-12-27 12:20:00 → ONT 2026-12-27 15:03:00; nonstop; 163 minutes. Local airport times.

2026-12-21 → 2026-12-27 · $378.00

  • Delta Air Lines DL4031: ONT 2026-12-21 17:38:00 → SEA 2026-12-21 20:43:00; nonstop; 185 minutes. Local airport times.
  • Delta Air Lines DL1016 / DL3879: SEA 2026-12-27 09:18:00 → ONT 2026-12-27 16:22:00; 1 stop(s) via SLC; 424 minutes. Local airport times.
    • DL1016: SEA 2026-12-27 09:18:00 → SLC 2026-12-27 12:31:00; layover at SLC: 178 minutes.
    • DL3879: SLC 2026-12-27 15:29:00 → ONT 2026-12-27 16:22:00.

More dates for this route