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Ontario → Seattle

Dec 2, 2026 · return Dec 5, 2026

ONT → SEA1 adulteconomyRound trip

11 flight options · 5 airlines

Nonstop flights

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

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

Round-trip total · 1 adult · Taxes included

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

Alaska Airlines
6:00 amONT
2h 51m
Nonstop
8:51 amSEA
Alaska Airlines
9:23 pmSEA
2h 36m
Nonstop
11:59 pmONT

Round-trip total · 1 adult · Taxes included

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

Alaska Airlines
5:36 pmONT
4h 52m
BOI · 1h 6m
10:28 pmSEA
Alaska Airlines
9:23 pmSEA
2h 36m
Nonstop
11:59 pmONT

Round-trip total · 1 adult · Taxes included

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

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

Wed, Dec 2 – Sat, Dec 5

Delta Air Lines
6:00 amONT
6h 36m
SLC · 2h 26m
12:36 pmSEA
Delta Air Lines
11:59 amSEA
2h 51m
Nonstop
2:50 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 routeOct 30, 2026 → Nov 2, 2026Oct 31, 2026 → Nov 7, 2026Nov 13, 2026 → Nov 16, 2026Nov 14, 2026 → Nov 21, 2026Nov 24, 2026 → Nov 29, 2026Nov 27, 2026 → Nov 30, 2026Nov 28, 2026 → Dec 5, 2026Dec 11, 2026 → Dec 14, 2026Dec 12, 2026 → Dec 19, 2026Dec 22, 2026 → Dec 27, 2026Dec 25, 2026 → Dec 28, 2026Dec 26, 2026 → Jan 2, 2027Dec 30, 2026 → Jan 2, 2027Jan 8, 2027 → Jan 11, 2027Jan 9, 2027 → Jan 16, 2027Jan 15, 2027 → Jan 18, 2027Jan 22, 2027 → Jan 25, 2027Jan 23, 2027 → Jan 30, 2027Feb 5, 2027 → Feb 8, 2027Feb 6, 2027 → Feb 13, 2027Feb 12, 2027 → Feb 15, 2027Mar 5, 2027 → Mar 8, 2027Mar 6, 2027 → Mar 13, 2027Mar 25, 2027 → Mar 29, 2027Apr 2, 2027 → Apr 5, 2027Apr 3, 2027 → Apr 10, 2027Apr 30, 2027 → May 3, 2027May 1, 2027 → May 8, 2027May 28, 2027 → May 31, 2027May 29, 2027 → Jun 5, 2027Jun 25, 2027 → Jun 28, 2027Jun 26, 2027 → Jul 3, 2027Jul 2, 2027 → Jul 6, 2027Jul 23, 2027 → Jul 26, 2027Jul 24, 2027 → Jul 31, 2027Aug 20, 2027 → Aug 23, 2027Aug 21, 2027 → Aug 28, 2027Sep 3, 2027 → Sep 6, 2027Sep 17, 2027 → Sep 20, 2027Oct 30, 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)
2026-12-02 → 2026-12-05Frontier AirlinesF92275 / F92276$145.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Alaska AirlinesAS571 / AS489$260.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Delta Air LinesDL4031 / DL4031$270.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Southwest AirlinesWN1053 + WN4083 / WN3105 + WN1383$270.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05United AirlinesUA2363 + UA2192 / UA2478 + UA552$290.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Alaska AirlinesAS607 / AS489$260.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Delta Air LinesDL4070 / DL4031$270.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Alaska AirlinesAS3380 + AS2016 / AS489$270.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Southwest AirlinesWN3326 + WN1586 / WN3105 + WN1383$270.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Southwest AirlinesWN3313 + WN4608 / WN3105 + WN1383$270.002026-10-29T01:52:37Z
2026-12-02 → 2026-12-05Delta Air LinesDL2708 + DL2995 / DL4031$280.002026-10-29T01:52:37Z

2026-12-02 → 2026-12-05 · $145.00

  • Frontier Airlines F92275: ONT 2026-12-02 06:00:00 → SEA 2026-12-02 09:03:00; nonstop; 183 minutes. Local airport times.
  • Frontier Airlines F92276: SEA 2026-12-05 10:50:00 → ONT 2026-12-05 13:38:00; nonstop; 168 minutes. Local airport times.

2026-12-02 → 2026-12-05 · $260.00

  • Alaska Airlines AS571: ONT 2026-12-02 16:09:00 → SEA 2026-12-02 18:56:00; nonstop; 167 minutes. Local airport times.
  • Alaska Airlines AS489: SEA 2026-12-05 21:23:00 → ONT 2026-12-05 23:59:00; nonstop; 156 minutes. Local airport times.

2026-12-02 → 2026-12-05 · $270.00

  • Delta Air Lines DL4031: ONT 2026-12-02 17:56:00 → SEA 2026-12-02 20:57:00; nonstop; 181 minutes. Local airport times.
  • Delta Air Lines DL4031: SEA 2026-12-05 11:59:00 → ONT 2026-12-05 14:50:00; nonstop; 171 minutes. Local airport times.

2026-12-02 → 2026-12-05 · $270.00

  • Southwest Airlines WN1053 / WN4083: ONT 2026-12-02 17:00:00 → SEA 2026-12-02 22:20:00; 1 stop(s) via LAS; 320 minutes. Local airport times.
    • WN1053: ONT 2026-12-02 17:00:00 → LAS 2026-12-02 18:05:00; layover at LAS: 85 minutes.
    • WN4083: LAS 2026-12-02 19:30:00 → SEA 2026-12-02 22:20:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-05 08:05:00 → ONT 2026-12-05 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-05 08:05:00 → SJC 2026-12-05 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-05 11:20:00 → ONT 2026-12-05 12:40:00.

2026-12-02 → 2026-12-05 · $290.00

  • United Airlines UA2363 / UA2192: ONT 2026-12-02 06:00:00 → SEA 2026-12-02 12:18:00; 1 stop(s) via SFO; 378 minutes. Local airport times.
    • UA2363: ONT 2026-12-02 06:00:00 → SFO 2026-12-02 07:30:00; layover at SFO: 155 minutes.
    • UA2192: SFO 2026-12-02 10:05:00 → SEA 2026-12-02 12:18:00.
  • United Airlines UA2478 / UA552: SEA 2026-12-05 15:24:00 → ONT 2026-12-05 22:53:00; 1 stop(s) via SFO; 449 minutes. Local airport times.
    • UA2478: SEA 2026-12-05 15:24:00 → SFO 2026-12-05 17:45:00; layover at SFO: 225 minutes.
    • UA552: SFO 2026-12-05 21:30:00 → ONT 2026-12-05 22:53:00.

2026-12-02 → 2026-12-05 · $260.00

  • Alaska Airlines AS607: ONT 2026-12-02 06:00:00 → SEA 2026-12-02 08:51:00; nonstop; 171 minutes. Local airport times.
  • Alaska Airlines AS489: SEA 2026-12-05 21:23:00 → ONT 2026-12-05 23:59:00; nonstop; 156 minutes. Local airport times.

2026-12-02 → 2026-12-05 · $270.00

  • Delta Air Lines DL4070: ONT 2026-12-02 11:57:00 → SEA 2026-12-02 14:56:00; nonstop; 179 minutes. Local airport times.
  • Delta Air Lines DL4031: SEA 2026-12-05 11:59:00 → ONT 2026-12-05 14:50:00; nonstop; 171 minutes. Local airport times.

2026-12-02 → 2026-12-05 · $270.00

  • Alaska Airlines AS3380 / AS2016: ONT 2026-12-02 17:36:00 → SEA 2026-12-02 22:28:00; 1 stop(s) via BOI; 292 minutes. Local airport times.
    • AS3380: ONT 2026-12-02 17:36:00 → BOI 2026-12-02 20:41:00; layover at BOI: 66 minutes.
    • AS2016: BOI 2026-12-02 21:47:00 → SEA 2026-12-02 22:28:00.
  • Alaska Airlines AS489: SEA 2026-12-05 21:23:00 → ONT 2026-12-05 23:59:00; nonstop; 156 minutes. Local airport times.

2026-12-02 → 2026-12-05 · $270.00

  • Southwest Airlines WN3326 / WN1586: ONT 2026-12-02 13:30:00 → SEA 2026-12-02 18:40:00; 1 stop(s) via SMF; 310 minutes. Local airport times.
    • WN3326: ONT 2026-12-02 13:30:00 → SMF 2026-12-02 14:55:00; layover at SMF: 105 minutes.
    • WN1586: SMF 2026-12-02 16:40:00 → SEA 2026-12-02 18:40:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-05 08:05:00 → ONT 2026-12-05 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-05 08:05:00 → SJC 2026-12-05 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-05 11:20:00 → ONT 2026-12-05 12:40:00.

2026-12-02 → 2026-12-05 · $270.00

  • Southwest Airlines WN3313 / WN4608: ONT 2026-12-02 16:05:00 → SEA 2026-12-02 21:40:00; 1 stop(s) via OAK; 335 minutes. Local airport times.
    • WN3313: ONT 2026-12-02 16:05:00 → OAK 2026-12-02 17:30:00; layover at OAK: 110 minutes.
    • WN4608: OAK 2026-12-02 19:20:00 → SEA 2026-12-02 21:40:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2026-12-05 08:05:00 → ONT 2026-12-05 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2026-12-05 08:05:00 → SJC 2026-12-05 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2026-12-05 11:20:00 → ONT 2026-12-05 12:40:00.

2026-12-02 → 2026-12-05 · $280.00

  • Delta Air Lines DL2708 / DL2995: ONT 2026-12-02 06:00:00 → SEA 2026-12-02 12:36:00; 1 stop(s) via SLC; 396 minutes. Local airport times.
    • DL2708: ONT 2026-12-02 06:00:00 → SLC 2026-12-02 08:49:00; layover at SLC: 146 minutes.
    • DL2995: SLC 2026-12-02 11:15:00 → SEA 2026-12-02 12:36:00.
  • Delta Air Lines DL4031: SEA 2026-12-05 11:59:00 → ONT 2026-12-05 14:50:00; nonstop; 171 minutes. Local airport times.

More dates for this route