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Ontario → Seattle

Dec 21, 2026 · return Jan 4, 2027

ONT → SEA1 adulteconomyRound trip

9 flight options · 4 airlines

Nonstop flights

Mon, Dec 21 – Mon, Jan 4

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 – Mon, Jan 4

Delta Air Lines
5:38 pmONT
3h 5m
Nonstop
8:43 pmSEA
Delta Air Lines
11:59 amSEA
2h 51m
Nonstop
2:50 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Mon, Jan 4

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

Round-trip total · 1 adult · Taxes included

One-stop flights

Mon, Dec 21 – Mon, Jan 4

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

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Mon, Jan 4

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 – Mon, Jan 4

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 – Mon, Jan 4

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 – Mon, Jan 4

Delta Air Lines
5:56 pmONT
3h 1m
Nonstop
8:57 pmSEA
Delta Air Lines
9:18 amSEA
7h 4m
SLC · 2h 58m
4:22 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Mon, Jan 4

Alaska Airlines
5:36 pmONT
4h 52m
BOI · 1h 6m
10:28 pmSEA
Alaska Airlines
9:50 amSEA
7h 6m
BOI · 3h 19m
4:56 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.

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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 → 2027-01-04Frontier AirlinesF92275 / F92276$166.762026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Delta Air LinesDL4031 / DL4031$310.502026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Alaska AirlinesAS571 / AS3087 + AS3380$308.502026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Southwest AirlinesWN3326 + WN1586 / WN3105 + WN1383$310.502026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Delta Air LinesDL4070 / DL4031$310.502026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Southwest AirlinesWN3313 + WN4608 / WN3105 + WN1383$310.502026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Southwest AirlinesWN1053 + WN4083 / WN3105 + WN1383$310.502026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Delta Air LinesDL4031 / DL1016 + DL3879$320.002026-10-29T01:52:37Z
2026-12-21 → 2027-01-04Alaska AirlinesAS3380 + AS2016 / AS3087 + AS3380$322.002026-10-29T01:52:37Z

2026-12-21 → 2027-01-04 · $166.76

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

2026-12-21 → 2027-01-04 · $310.50

  • 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 DL4031: SEA 2027-01-04 11:59:00 → ONT 2027-01-04 14:50:00; nonstop; 171 minutes. Local airport times.

2026-12-21 → 2027-01-04 · $308.50

  • 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 AS3087 / AS3380: SEA 2027-01-04 09:50:00 → ONT 2027-01-04 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
    • AS3087: SEA 2027-01-04 09:50:00 → BOI 2027-01-04 12:21:00; layover at BOI: 199 minutes.
    • AS3380: BOI 2027-01-04 15:40:00 → ONT 2027-01-04 16:56:00.

2026-12-21 → 2027-01-04 · $310.50

  • 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 2027-01-04 08:05:00 → ONT 2027-01-04 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2027-01-04 08:05:00 → SJC 2027-01-04 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2027-01-04 11:20:00 → ONT 2027-01-04 12:40:00.

2026-12-21 → 2027-01-04 · $310.50

  • Delta Air Lines DL4070: ONT 2026-12-21 11:57:00 → SEA 2026-12-21 14:56:00; nonstop; 179 minutes. Local airport times.
  • Delta Air Lines DL4031: SEA 2027-01-04 11:59:00 → ONT 2027-01-04 14:50:00; nonstop; 171 minutes. Local airport times.

2026-12-21 → 2027-01-04 · $310.50

  • 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 2027-01-04 08:05:00 → ONT 2027-01-04 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2027-01-04 08:05:00 → SJC 2027-01-04 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2027-01-04 11:20:00 → ONT 2027-01-04 12:40:00.

2026-12-21 → 2027-01-04 · $310.50

  • 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 2027-01-04 08:05:00 → ONT 2027-01-04 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2027-01-04 08:05:00 → SJC 2027-01-04 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2027-01-04 11:20:00 → ONT 2027-01-04 12:40:00.

2026-12-21 → 2027-01-04 · $320.00

  • 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 DL1016 / DL3879: SEA 2027-01-04 09:18:00 → ONT 2027-01-04 16:22:00; 1 stop(s) via SLC; 424 minutes. Local airport times.
    • DL1016: SEA 2027-01-04 09:18:00 → SLC 2027-01-04 12:31:00; layover at SLC: 178 minutes.
    • DL3879: SLC 2027-01-04 15:29:00 → ONT 2027-01-04 16:22:00.

2026-12-21 → 2027-01-04 · $322.00

  • 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 AS3087 / AS3380: SEA 2027-01-04 09:50:00 → ONT 2027-01-04 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
    • AS3087: SEA 2027-01-04 09:50:00 → BOI 2027-01-04 12:21:00; layover at BOI: 199 minutes.
    • AS3380: BOI 2027-01-04 15:40:00 → ONT 2027-01-04 16:56:00.

More dates for this route