$188+ Cheap flights from Ontario to Seattle (SEA)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/21. Fares are subject to change and may not be available on all flights or dates of travel.
YYZ — SEA
Oct 30 — Nov 61
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to Seattle with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Ontario to Seattle
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Cheapest flights from Ontario to SeattleExplore the most affordable flight options available from Ontario to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 30, 2026.
Explore the most affordable flight options available from Ontario to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 30, 2026.
This Kiwi.com deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/2412:00 pm -
1 stop9h 45m
Fri 10/303:30 pm -
1 stop11h 30m
Deal found 9/28![WestJet logo]()
$317
This Trip.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:00 pm -
1 stop9h 45m
Fri 10/2310:30 am -
1 stop9h 15m
Deal found 9/27![WestJet logo]()
$321
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/106:10 am -
2 stops15h 35m
Tue 10/137:35 pm -
1 stop7h 10m
Deal found 9/26![WestJet logo]()
$322
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/221:30 pm -
1 stop8h 15m
Fri 10/303:30 pm -
1 stop11h 30m
Deal found 9/27![WestJet logo]()
$324
This FlightHub deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/1112:40 pm -
2 stops9h 05m
Thu 11/122:30 pm -
2 stops12h 15m
Deal found 9/27![WestJet logo]()
$326
This WestJet deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:00 pm -
1 stop9h 45m
Wed 10/147:35 pm -
1 stop8h 20m
Deal found 9/26![WestJet logo]()
$327
This Justfly.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/177:00 am -
2 stops9h 40m
Fri 12/252:30 pm -
1 stop17h 25m
Deal found 9/27![WestJet logo]()
$328
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/127:30 am -
1 stop9h 10m
Tue 11/172:30 pm -
1 stop25h 50m
Deal found 9/26![WestJet logo]()
$329
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/148:40 pm -
1 stop25h 05m
Tue 10/207:35 pm -
1 stop21h 15m
Deal found 9/26![WestJet logo]()
$330
This Justfly.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/156:10 am -
2 stops15h 35m
Fri 10/167:35 pm -
1 stop7h 10m
Deal found 9/26![WestJet logo]()
$330
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:10 pm -
1 stop18h 30m
Tue 10/207:35 pm -
1 stop18h 40m
Deal found 9/26![WestJet logo]()
$331
This FlightHub deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/136:10 am -
2 stops30h 30m
Fri 10/2310:30 am -
2 stops8h 05m
Deal found 9/27![WestJet logo]()
$331
Best flights from Ontario to SeattleDiscover carefully curated flight deals from Ontario to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 30, 2026.
Discover carefully curated flight deals from Ontario to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 30, 2026.
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/148:40 pm -
1 stop25h 05m
Tue 10/207:35 pm -
1 stop21h 15m
Deal found 9/26![WestJet logo]()
$330
This Mytrip deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/188:40 pm -
1 stop25h 05m
Fri 10/237:35 pm -
1 stop16h 25m
Deal found 9/25![Multiple Airlines logo]()
$384
This United Airlines deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/1410:37 am -
1 stop11h 15m
Fri 10/1611:14 pm -
1 stop12h 03m
Deal found 9/25![United Airlines logo]()
$395
This Delta deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/3011:38 am -
1 stop10h 26m
Mon 11/1611:40 pm -
1 stop8h 29m
Deal found 9/27![Delta logo]()
$429
This Alaska Airlines deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/214:55 pm -
Nonstop5h 31m
Tue 10/278:20 am -
Nonstop4h 45m
Deal found 9/26![Alaska Airlines logo]()
$505
This Air Canada deal was found by Cheapflights users on 9/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/123:25 pm -
1 stop8h 34m
Sat 11/147:05 pm -
2 stops16h 37m
Deal found 9/29![Air Canada logo]()
$640
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:10 pm -
1 stop18h 30m
Tue 10/207:35 pm -
1 stop18h 40m
Deal found 9/26![WestJet logo]()
$331
This Trip.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/166:10 pm -
1 stop27h 35m
Mon 10/197:35 pm -
1 stop18h 40m
Deal found 9/26![WestJet logo]()
$338
This Trip.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/246:40 am -
1 stop10h 00m
Mon 11/305:48 pm -
1 stop8h 47m
Deal found 9/25![Multiple Airlines logo]()
$398
This United Airlines deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/236:00 am -
1 stop17h 37m
Mon 10/267:35 pm -
2 stops14h 36m
Deal found 9/26![United Airlines logo]()
$399
This Trip.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:10 pm -
1 stop18h 30m
Sun 10/187:35 pm -
1 stop18h 40m
Deal found 9/25![WestJet logo]()
$339
This United Airlines deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/236:00 am -
1 stop12h 51m
Sun 11/110:56 pm -
1 stop12h 13m
Deal found 9/26![United Airlines logo]()
$399
This Trip.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/148:40 pm -
1 stop16h 00m
Sun 10/187:35 pm -
1 stop21h 15m
Deal found 9/25![WestJet logo]()
$340
This Delta deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/106:30 am -
2 stops11h 55m
Tue 11/1711:40 pm -
1 stop8h 29m
Deal found 9/26![Delta logo]()
$466
This United deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/103:10 pm -
1 stop10h 26m
Sun 10/183:00 pm -
2 stops16h 55m
Deal found 9/25![Multiple Airlines logo]()
$426
This United Airlines deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/309:45 am -
1 stop14h 11m
Tue 11/310:56 pm -
1 stop12h 13m
Deal found 9/25![United Airlines logo]()
$407
This Trip.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:10 pm -
1 stop27h 35m
Mon 10/197:35 pm -
1 stop18h 40m
Deal found 9/26![WestJet logo]()
$340
This Delta deal was found by Cheapflights users on 9/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/49:40 am -
1 stop8h 05m
Mon 11/911:40 pm -
1 stop8h 29m
Deal found 9/29![Delta logo]()
$466
This Alaska Airlines deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/135:15 pm -
Nonstop5h 30m
Tue 11/178:19 am -
Nonstop4h 46m
Deal found 9/27![Alaska Airlines logo]()
$513
This Trip.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/118:40 pm -
1 stop16h 00m
Thu 10/157:35 pm -
1 stop21h 15m
Deal found 9/27![WestJet logo]()
$341
This United Airlines deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/276:15 am -
1 stop15h 48m
Thu 12/3110:55 am -
1 stop7h 28m
Deal found 9/25![United Airlines logo]()
$418
This Delta deal was found by Cheapflights users on 9/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/301:34 pm -
1 stop8h 30m
Wed 11/46:00 am -
1 stop8h 19m
Deal found 9/29![Delta logo]()
$466
This Alaska Airlines deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/35:15 pm -
Nonstop5h 30m
Sun 11/88:19 am -
Nonstop4h 46m
Deal found 9/26![Alaska Airlines logo]()
$513
This Mytrip deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/246:05 am -
3 stops15h 27m
Sat 10/317:05 pm -
2 stops17h 20m
Deal found 9/28![Multiple Airlines logo]()
$492
This United Airlines deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/302:00 pm -
2 stops12h 15m
Mon 1/47:10 pm -
2 stops17h 00m
Deal found 9/27![United Airlines logo]()
$418
This Alaska Airlines deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/244:55 pm -
Nonstop5h 31m
Fri 10/308:20 am -
Nonstop4h 45m
Deal found 9/25![Alaska Airlines logo]()
$522
This WestJet deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:10 am -
1 stop15h 35m
Thu 10/227:35 pm -
1 stop6h 45m
Deal found 9/27![WestJet logo]()
$359
This Delta deal was found by Cheapflights users on 9/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/15:49 pm -
1 stop7h 16m
Thu 11/511:10 pm -
1 stop6h 39m
Deal found 9/29![Delta logo]()
$481
This Air Canada deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/245:30 am -
2 stops12h 07m
Mon 11/308:40 am -
2 stops10h 12m
Deal found 9/25![Air Canada logo]()
$646
This United Airlines deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/283:10 pm -
1 stop9h 29m
Mon 1/47:10 pm -
2 stops17h 00m
Deal found 9/27![United Airlines logo]()
$418
Last-minute flights from Ontario to SeattleDiscover last-minute flight deals from Ontario to Seattle. Data last updated September 30, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Seattle. Data last updated September 30, 2026 and is based on user searches.
This Trip.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:00 pm -
1 stop9h 45m
Fri 10/2310:30 am -
1 stop9h 15m
Deal found 9/27![WestJet logo]()
$321
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/106:10 am -
2 stops15h 35m
Tue 10/137:35 pm -
1 stop7h 10m
Deal found 9/26![WestJet logo]()
$322
This WestJet deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:00 pm -
1 stop9h 45m
Wed 10/147:35 pm -
1 stop8h 20m
Deal found 9/26![WestJet logo]()
$327
This FlightHub deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/1112:40 pm -
2 stops9h 05m
Thu 11/122:30 pm -
2 stops12h 15m
Deal found 9/27![WestJet logo]()
$326
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/1110:20 pm -
2 stops14h 20m
Sat 10/2410:30 am -
1 stop7h 45m
Deal found 9/27![WestJet logo]()
$332
This FlightHub deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/136:10 am -
2 stops30h 30m
Fri 10/2310:30 am -
2 stops8h 05m
Deal found 9/27![WestJet logo]()
$331
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/148:40 pm -
1 stop25h 05m
Tue 10/207:35 pm -
1 stop21h 15m
Deal found 9/26![WestJet logo]()
$330
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:10 pm -
1 stop18h 30m
Tue 10/207:35 pm -
1 stop18h 40m
Deal found 9/26![WestJet logo]()
$331
This FlightHub deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:10 pm -
1 stop18h 30m
Sun 10/187:35 pm -
1 stop18h 40m
Deal found 9/25![WestJet logo]()
$332
This Justfly.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/156:10 am -
2 stops15h 35m
Fri 10/167:35 pm -
1 stop7h 10m
Deal found 9/26![WestJet logo]()
$330
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/221:30 pm -
1 stop8h 15m
Fri 10/303:30 pm -
1 stop11h 30m
Deal found 9/27![WestJet logo]()
$324
This Kiwi.com deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/2412:00 pm -
1 stop9h 45m
Fri 10/303:30 pm -
1 stop11h 30m
Deal found 9/28![WestJet logo]()
$317
One-way flights from Ontario to SeattleSearch for one-way flight options from Ontario to Seattle. Find affordable one-way fares based on user searches. Data last updated September 30, 2026.
Search for one-way flight options from Ontario to Seattle. Find affordable one-way fares based on user searches. Data last updated September 30, 2026.
This Trip.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:10 pm -
1 stop18h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/25![WestJet logo]()
$188
This Trip.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/116:10 pm -
1 stop18h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![WestJet logo]()
$189
This Justfly.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/206:10 pm -
1 stop18h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/25![WestJet logo]()
$190
This Justfly.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/226:10 pm -
1 stop18h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/25![WestJet logo]()
$191
This Trip.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/123:25 pm -
1 stop25h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![WestJet logo]()
$193
This FlightHub deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/83:25 pm -
1 stop25h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![WestJet logo]()
$194
This FlightHub deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/136:10 pm -
1 stop27h 35m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![WestJet logo]()
$199
This Kissandfly.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:15 pm -
2 stops27h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![WestJet logo]()
$202
This Mytrip deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/166:10 pm -
1 stop18h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![WestJet logo]()
$202
This Trip.com deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/124:15 pm -
1 stop24h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/28![WestJet logo]()
$213
This Kissandfly.com deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/213:25 pm -
1 stop25h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/28![WestJet logo]()
$216
This FlightHub deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/43:25 pm -
1 stop25h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![WestJet logo]()
$220
Find flight deals from Ontario to Seattle
Keep the following information in mind while searching for Ontario to Seattle flight deals. Data was last updated September 30, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $312 (FlightHub) |
One-way from | $184 (Kissandfly.com) |
Popular in | June |
Cheapest in | February |
Average price | $389 |
Good round-trip deal | $435 or less |
Good one-way deal | $244 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 30, 2026.
Use the filters below to find and compare flights from Ontario to Seattle that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
HamiltonSeattle
YHM Hamilton - SEA Seattle/Tacoma Intl
YHMSEA
Hamilton
Fri 10/23
6:10 pm-6:45 pm
1 stop27h 35m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$188
HamiltonSeattle
YHM Hamilton - SEA Seattle/Tacoma Intl
YHMSEA
Hamilton
Tue 10/20
6:10 pm-9:40 am
1 stop18h 30m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$189
HamiltonSeattle
YHM Hamilton - SEA Seattle/Tacoma Intl
YHMSEA
Hamilton
Sun 10/11
6:10 pm-9:40 am
1 stop18h 30m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$189
HamiltonSeattle
YHM Hamilton - SEA Seattle/Tacoma Intl
YHMSEA
Hamilton
Thu 11/12
3:25 pm-1:40 pm
1 stop25h 15m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$193
HamiltonSeattle
YHM Hamilton - SEA Seattle/Tacoma Intl
YHMSEA
Hamilton
Tue 12/8
3:25 pm-1:40 pm
1 stop25h 15m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$194
HamiltonSeattle
YHM Hamilton - SEA Seattle/Tacoma Intl
YHMSEA
Hamilton
Thu 10/22
6:10 pm-9:40 am
1 stop18h 30m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$199
OttawaSeattle
YOW Ottawa - SEA Seattle/Tacoma Intl
YOWSEA
Ottawa
Wed 10/21
6:00 am-3:51 pm
3 stops12h 51m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$227
TorontoSeattle
YYZ Toronto Pearson Intl - SEA Seattle/Tacoma Intl
YYZSEA
Toronto Pearson Intl
Tue 11/10
2:20 pm-9:58 pm
1 stop10h 38m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$229
OttawaSeattle
YOW Ottawa - SEA Seattle/Tacoma Intl
YOWSEA
Ottawa
Tue 11/10
6:00 am-10:51 pm
2 stops19h 51m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$230
OttawaSeattle
YOW Ottawa - SEA Seattle/Tacoma Intl
YOWSEA
Ottawa
Sat 12/5
6:15 am-4:18 pm
1 stop13h 03m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$230
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Ontario to Seattle
Have a flexible travel schedule? Discover the best time to fly to Seattle from Ontario with our price prediction graph.
YYZ-SEA
YKF-SEA
YHM-SEA
YOW-SEA
YXU-SEA
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from Ontario to Seattle
CAON-SEA
YYZ-SEA
YKF-SEA
YHM-SEA
YOW-SEA
What is the cheapest month to book a flight from Region of Ontario to Seattle?
Currently, February is the cheapest month in which you can book a flight from Region of Ontario to Seattle (average of $249). Flying from Region of Ontario to Seattle in July is currently the most expensive (average of $467). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from ON to SEA?
Find hourly flight availability from Ontario to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 30, 2026.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Region of Ontario to Seattle as you normally would.
Weekly flight availability from Region of Ontario to Seattle
Explore weekly flight availability from Ontario to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated September 30, 2026.
The most flights from CAON to SEA are scheduled on a Tuesday (4 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (1 on average).
How much does it cost to fly round-trip from Region of Ontario to Seattle?
Airfare is typical for this route at the moment.
Region of Ontario to Seattle flights typically cost between $317 and $516 in October.The cheapest round-trip price found within the last 5 days was $317 on WestJet (Oct 24-Oct 30).
How far ahead should I book a flight from Region of Ontario to Seattle?
The price you pay for your flight from Region of Ontario to Seattle may vary depending on when you book. For the best chance of a lower fare, look to book 74 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
Related info for your journey
Find useful and relevant information for your journey from Ontario to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Seattle?
Book flights to Seattle if you plan to visit one of these locationsSeaTac
Renton
Tacoma
Lacey
Leavenworth
Olympia
Tukwila
Snoqualmie
Puyallup
Lynnwood
Centralia
Kent
Tumwater
Ocean Shores
Ellensburg
Issaquah
Marysville
Lakewood
Fife
Poulsbo
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
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Alternative routes for Ontario to Seattle
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Complete your trip
Complete your trip to Seattle by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Ontario to Seattle by cabin class
Find flights from Ontario to Seattle, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Ontario and Seattle flights
Browse other Ontario and Seattle flight options. Last updated on September 30, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Other flights to Seattle
Explore flights to Seattle departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 30, 2026.
Top 5 airlines flying from Ontario to Seattle
Discover the top 5 airlines that operate flights from Ontario to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 30, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$202 | Average$437 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$206 | Average$446 | FlexibilityNo cancel fee | On-time67% | |
| Cheapest$209 | Average$455 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$213 | Average$395 | FlexibilityNo cancel fee | On-time60% | |
| Cheapest$219 | Average$464 | FlexibilityNo cancel fee | On-time69% |