Travel with Axel,
get the best price.

Ontario → Seattle

Jun 25, 2027 · return Jun 28, 2027

ONT → SEA1 adulteconomyRound trip

9 flight options · 4 airlines

Nonstop flights

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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

Fri, Jun 25 – Mon, Jun 28

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 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)
2027-06-25 → 2027-06-28Frontier AirlinesF92275 / F92276$200.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Delta Air LinesDL4031 / DL4031$350.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Southwest AirlinesWN3313 + WN4608 / WN3105 + WN1383$340.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Alaska AirlinesAS571 / AS3087 + AS3380$345.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Delta Air LinesDL4070 / DL4031$350.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Southwest AirlinesWN1053 + WN4083 / WN3105 + WN1383$340.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Southwest AirlinesWN3326 + WN1586 / WN3105 + WN1383$340.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Alaska AirlinesAS3380 + AS2016 / AS3087 + AS3380$350.002026-10-29T01:52:37Z
2027-06-25 → 2027-06-28Delta Air LinesDL4031 / DL1016 + DL3879$355.002026-10-29T01:52:37Z

2027-06-25 → 2027-06-28 · $200.00

  • Frontier Airlines F92275: ONT 2027-06-25 06:00:00 → SEA 2027-06-25 09:03:00; nonstop; 183 minutes. Local airport times.
  • Frontier Airlines F92276: SEA 2027-06-28 10:50:00 → ONT 2027-06-28 13:38:00; nonstop; 168 minutes. Local airport times.

2027-06-25 → 2027-06-28 · $350.00

  • Delta Air Lines DL4031: ONT 2027-06-25 17:56:00 → SEA 2027-06-25 20:57:00; nonstop; 181 minutes. Local airport times.
  • Delta Air Lines DL4031: SEA 2027-06-28 11:59:00 → ONT 2027-06-28 14:50:00; nonstop; 171 minutes. Local airport times.

2027-06-25 → 2027-06-28 · $340.00

  • Southwest Airlines WN3313 / WN4608: ONT 2027-06-25 16:05:00 → SEA 2027-06-25 21:40:00; 1 stop(s) via OAK; 335 minutes. Local airport times.
    • WN3313: ONT 2027-06-25 16:05:00 → OAK 2027-06-25 17:30:00; layover at OAK: 110 minutes.
    • WN4608: OAK 2027-06-25 19:20:00 → SEA 2027-06-25 21:40:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2027-06-28 08:05:00 → ONT 2027-06-28 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2027-06-28 08:05:00 → SJC 2027-06-28 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2027-06-28 11:20:00 → ONT 2027-06-28 12:40:00.

2027-06-25 → 2027-06-28 · $345.00

  • Alaska Airlines AS571: ONT 2027-06-25 16:09:00 → SEA 2027-06-25 18:56:00; nonstop; 167 minutes. Local airport times.
  • Alaska Airlines AS3087 / AS3380: SEA 2027-06-28 09:50:00 → ONT 2027-06-28 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
    • AS3087: SEA 2027-06-28 09:50:00 → BOI 2027-06-28 12:21:00; layover at BOI: 199 minutes.
    • AS3380: BOI 2027-06-28 15:40:00 → ONT 2027-06-28 16:56:00.

2027-06-25 → 2027-06-28 · $350.00

  • Delta Air Lines DL4070: ONT 2027-06-25 11:57:00 → SEA 2027-06-25 14:56:00; nonstop; 179 minutes. Local airport times.
  • Delta Air Lines DL4031: SEA 2027-06-28 11:59:00 → ONT 2027-06-28 14:50:00; nonstop; 171 minutes. Local airport times.

2027-06-25 → 2027-06-28 · $340.00

  • Southwest Airlines WN1053 / WN4083: ONT 2027-06-25 17:00:00 → SEA 2027-06-25 22:20:00; 1 stop(s) via LAS; 320 minutes. Local airport times.
    • WN1053: ONT 2027-06-25 17:00:00 → LAS 2027-06-25 18:05:00; layover at LAS: 85 minutes.
    • WN4083: LAS 2027-06-25 19:30:00 → SEA 2027-06-25 22:20:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2027-06-28 08:05:00 → ONT 2027-06-28 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2027-06-28 08:05:00 → SJC 2027-06-28 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2027-06-28 11:20:00 → ONT 2027-06-28 12:40:00.

2027-06-25 → 2027-06-28 · $340.00

  • Southwest Airlines WN3326 / WN1586: ONT 2027-06-25 13:30:00 → SEA 2027-06-25 18:40:00; 1 stop(s) via SMF; 310 minutes. Local airport times.
    • WN3326: ONT 2027-06-25 13:30:00 → SMF 2027-06-25 14:55:00; layover at SMF: 105 minutes.
    • WN1586: SMF 2027-06-25 16:40:00 → SEA 2027-06-25 18:40:00.
  • Southwest Airlines WN3105 / WN1383: SEA 2027-06-28 08:05:00 → ONT 2027-06-28 12:40:00; 1 stop(s) via SJC; 275 minutes. Local airport times.
    • WN3105: SEA 2027-06-28 08:05:00 → SJC 2027-06-28 10:20:00; layover at SJC: 60 minutes.
    • WN1383: SJC 2027-06-28 11:20:00 → ONT 2027-06-28 12:40:00.

2027-06-25 → 2027-06-28 · $350.00

  • Alaska Airlines AS3380 / AS2016: ONT 2027-06-25 17:36:00 → SEA 2027-06-25 22:28:00; 1 stop(s) via BOI; 292 minutes. Local airport times.
    • AS3380: ONT 2027-06-25 17:36:00 → BOI 2027-06-25 20:41:00; layover at BOI: 66 minutes.
    • AS2016: BOI 2027-06-25 21:47:00 → SEA 2027-06-25 22:28:00.
  • Alaska Airlines AS3087 / AS3380: SEA 2027-06-28 09:50:00 → ONT 2027-06-28 16:56:00; 1 stop(s) via BOI; 426 minutes. Local airport times.
    • AS3087: SEA 2027-06-28 09:50:00 → BOI 2027-06-28 12:21:00; layover at BOI: 199 minutes.
    • AS3380: BOI 2027-06-28 15:40:00 → ONT 2027-06-28 16:56:00.

2027-06-25 → 2027-06-28 · $355.00

  • Delta Air Lines DL4031: ONT 2027-06-25 17:38:00 → SEA 2027-06-25 20:43:00; nonstop; 185 minutes. Local airport times.
  • Delta Air Lines DL1016 / DL3879: SEA 2027-06-28 09:18:00 → ONT 2027-06-28 16:22:00; 1 stop(s) via SLC; 424 minutes. Local airport times.
    • DL1016: SEA 2027-06-28 09:18:00 → SLC 2027-06-28 12:31:00; layover at SLC: 178 minutes.
    • DL3879: SLC 2027-06-28 15:29:00 → ONT 2027-06-28 16:22:00.

More dates for this route