Cheap Flights from Ontario, CA to Seattle, WA from $164

On Cheapflightsplus.com you will find 3 direct and 24 connecting flights from Ontario to Seattle. You can compare airfare deals from 4 airlines and multiple travel sites from $164, book and save on cheap plane tickets and last minute offers. Also check out ONT-SEA flight schedule to find best flight time, convenient departure and arrival airports.

Flight Information

Below we will explain in detail what the flights cost on the destination from Ontario to Seattle depends on and how to choose the most interesting flight option for you.

Distance between Ontario and Seattle is 1540 miles. Time difference between the cities is 0h. Airplanes depart 06:00 to 23:59 from 2 Ontario airports and arrive 06:00 to 23:59 to 3 Seattle airports. Average flight time is 2h 51m.

  • The fastest flight 2h 51m
  • Average flight time 2h 51m
  • The earliest flight 06:00
  • The latest flight 23:59
  • Distance 957 ml

The cheapest months to travel to Seattle are january (from 164 $).

What is the lowest airfare Ontario to Seattle?

The cheapest plane ticket found by our users is $164. This airfare is for economy class on one-way F92275 flight by Frontier Airlines for January 5, 2026 which leaves Ontario Int. in Ontario at 14:45 am and arrives at Seattle Seattle-Tacoma Intl at 17:38.

Economy class
$164
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Business class
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First class
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Flight Schedule Ontario (California) to Seattle (Washington)

06:00 — 00:42+1day
18h 42m flight time
Find flight
from$476
06:00 — 07:07 Ontario — Las Vegas
F92232 Frontier Airlines
8h 40m stop
15:47 — 17:04 Las Vegas — Los Angeles
NK1900 Spirit Airlines
4h 32m stop
21:36 — 00:42 Los Angeles — Seattle
F91177 Frontier Airlines
06:00 — 00:42+1day
18h 42m flight time
Find flight
from$509
06:00 — 07:07 Ontario — Las Vegas
F92232 Frontier Airlines
3h 48m stop
10:55 — 12:16 Las Vegas — Los Angeles
F93291 Frontier Airlines
9h 20m stop
21:36 — 00:42 Los Angeles — Seattle
F91177 Frontier Airlines
06:45 — 17:51+1day
35h 6m flight time
Find flight
from$550
06:45 — 10:06 Ontario — Denver
F91500 Frontier Airlines
12h 31m stop
22:37 — 23:42 Denver — Las Vegas
F9777 Frontier Airlines
15h 18m stop
15:00 — 17:51 Las Vegas — Seattle
F94667 Frontier Airlines
08:14 — 17:51+1day
33h 37m flight time
Find flight
from$473
08:14 — 13:15 Ontario — Dallas
F91406 Frontier Airlines
9h 22m stop
22:37 — 23:44 Dallas — Las Vegas
F93885 Frontier Airlines
15h 16m stop
15:00 — 17:51 Las Vegas — Seattle
F94667 Frontier Airlines
08:14 — 17:51+1day
33h 37m flight time
Find flight
from$588
08:14 — 13:15 Ontario — Dallas
F91406 Frontier Airlines
18h 45m stop
08:00 — 09:13 Dallas — Las Vegas
F91961 Frontier Airlines
5h 47m stop
15:00 — 17:51 Las Vegas — Seattle
F94667 Frontier Airlines
08:14 — 17:51+1day
33h 37m flight time
Find flight
from$691
08:14 — 13:15 Ontario — Dallas
F91406 Frontier Airlines
4h 29m stop
17:44 — 18:51 Dallas — Las Vegas
F91051 Frontier Airlines
20h 9m stop
15:00 — 17:51 Las Vegas — Seattle
F94667 Frontier Airlines
14:45 — 17:38
2h 53m flight time
Find flight
from$164
Ontario — Seattle
F92275 Frontier Airlines
18:00 — 17:51+1day
23h 51m flight time
Find flight
from$166
18:00 — 19:11 Ontario — Las Vegas
F94758 Frontier Airlines
19h 49m stop
15:00 — 17:51 Las Vegas — Seattle
F94667 Frontier Airlines
18:00 — 21:00+1day
27h flight time
Find flight
from$726
18:00 — 19:11 Ontario — Las Vegas
F94758 Frontier Airlines
12h 44m stop
07:55 — 11:36 Las Vegas — San Jose del Cabo
HA4777 Hawaiian Airlines
5h 34m stop
17:10 — 21:00 San Jose del Cabo — Seattle
AS1401 Alaska Airlines
18:20 — 17:51+1day
23h 31m flight time
Find flight
from$714
18:20 — 23:42 Ontario — Houston
F93132 Frontier Airlines
10h 13m stop
09:55 — 11:15 Houston — Las Vegas
NK2303 Spirit Airlines
3h 45m stop
15:00 — 17:51 Las Vegas — Seattle
F94667 Frontier Airlines
18:37 — 00:42+2days
30h 5m flight time
Find flight
from$493
18:37 — 19:48 Ontario — Las Vegas
F94758 Frontier Airlines
10h 12m stop
06:00 — 07:18 Las Vegas — Los Angeles
NK1984 Spirit Airlines
14h 18m stop
21:36 — 00:42 Los Angeles — Seattle
F91177 Frontier Airlines
18:37 — 18:53+1day
24h 16m flight time
Find flight
from$545
18:37 — 19:48 Ontario — Las Vegas
F94758 Frontier Airlines
10h 42m stop
06:30 — 08:48 Las Vegas — Phoenix
F94048 Frontier Airlines
7h 45m stop
16:33 — 18:53 Phoenix — Seattle
F91723 Frontier Airlines
18:39 — 00:59+1day
6h 20m flight time
Find flight
from$619
18:39 — 20:10 Ontario — San Francisco
UA698 United Airlines
2h 38m stop
22:48 — 00:59 San Francisco — Seattle
UA2462 United Airlines
19:19 — 22:10
2h 51m flight time
Find flight
from$314
Ontario — Seattle
HA6358 Hawaiian Airlines
19:19 — 22:10
2h 51m flight time
Find flight
from$319
Ontario — Seattle
AS594 Alaska Airlines
Full flight schedule will help you in detecting at what time planes fly from Ontario to Seattle. You can also specify the concrete flights and airlines on the route and how long the flight actually is. Use the calendar for today, tomorrow or other specific date as some flights are available only on certain days of the week.
*Departure and arrival times - local. Updated on February 23, 2026.

Popular Airlines on the Route

The flight Ontario — Seattle is served by 4 regular airlines and 1 low-cost airline. Most of the flights on this route are operated by Alaska Airlines - 1 departures per week at the price of from $ 319 . And the most expensive tickets are offered by United Airlines airline - from $ 1237.

Direct flights

There are 3 nonstop flights on the route. The fastest direct flight is HA6358 by Hawaiian Airlines takes 2h 51m and the cheapest is F92275 by Frontier Airlines for $164.

  • AS - Alaska Airlines
    from $319
    Find
  • F9 - Frontier Airlines
    from $164
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  • HA - Hawaiian Airlines
    from $314
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See more direct flights

Connecting Flights

There are 24 flights with layovers on the route. The fastest connecting flight is UA698 by United Airlines takes 6h 20m and the cheapest is F92275 by Frontier Airlines for $166.

  • F9 - Frontier Airlines
    from $166
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  • UA - United Airlines
    from $619
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See more connecting flights

Airports

You can fly from Ontario to Seattle from 2 airports (Ontario Int., International Heliport).

Ontario airports

  • Ontario Int.-ONT
    from $164
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  • International Heliport-JIO
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Seattle airports

  • Boeing Field International Airport-BFI
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  • Seattle-Tacoma Intl-SEA
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  • Kenmore Air Harbor SPB-LKE
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How to book a plane ticket yourself?

How to book an air ticket yourself?
  • Fill in the search parameters — cities of departure and destination, departure and return dates and click «Find flights»
  • Select the best flight that you like. Please, check the airports of departure and arrival. Select the best fare, but pay attention to the following flight details - airports of departure and arrival, flight duration and layovers. Please use filters and sort to find the best flight.
  • Click «Buy» when you are ready — our system will redirect you to the site that sells the selected flight ticket.
  • Fill in all passenger and payment information — passport and contact information, please double check all passengers’ names and make a payment for your itinerary.
  • That's it — you will receive an email with your e-ticket usually within 10 minutes after your flight is confirmed. Please, print the e-ticket and have it with you at the airport. You would need to have only a passport and/or a required form of ID to travel. Please, check your Visa requirements if you travel outside of the United States or Canada.

    To find a plane ticket, please select dates.

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