$170+ Cheap flights from Seattle (SEA) to Ontario
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 11/24. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — YYZ
Nov 21 — Nov 281
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Ontario 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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Cheapest flights from Seattle to OntarioExplore the most affordable flight options available from Seattle to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 22, 2026.
Explore the most affordable flight options available from Seattle to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 22, 2026.
This Justfly.com deal was found by Cheapflights users on 10/21. 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 11/172:30 pm -
2 stops12h 15m
Tue 11/247:30 am -
1 stop9h 10m
Deal found 10/21![WestJet logo]()
$366
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 12/242:30 pm -
2 stops12h 15m
Thu 12/316:10 am -
1 stop10h 30m
Deal found 10/21![WestJet logo]()
$368
This deal was found by Cheapflights users on 10/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/313:20 pm -
1 stop11h 40m
Thu 11/56:10 am -
1 stop10h 30m
Deal found 10/18![WestJet logo]()
$369
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
Mon 12/212:30 pm -
2 stops12h 15m
Tue 1/57:30 am -
1 stop9h 10m
Deal found 10/21![WestJet logo]()
$373
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 12/32:30 pm -
2 stops12h 15m
Wed 12/97:30 am -
1 stop9h 10m
Deal found 10/21![WestJet logo]()
$375
This Kiwi.com deal was found by Cheapflights users on 10/17. 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 12/62:30 pm -
2 stops12h 15m
Tue 12/87:30 am -
1 stop9h 10m
Deal found 10/17![WestJet logo]()
$376
This Kiwi.com deal was found by Cheapflights users on 10/17. 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.
Tue 12/12:30 pm -
2 stops12h 15m
Tue 12/87:30 am -
1 stop9h 10m
Deal found 10/17![WestJet logo]()
$378
This Kiwi.com deal was found by Cheapflights users on 10/19. 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.
Tue 11/242:30 pm -
2 stops12h 15m
Tue 12/17:30 am -
1 stop9h 10m
Deal found 10/19![WestJet logo]()
$381
This Kiwi.com deal was found by Cheapflights users on 10/19. 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 11/282:20 pm -
2 stops12h 25m
Tue 12/17:30 am -
1 stop9h 10m
Deal found 10/19![WestJet logo]()
$383
This Kiwi.com deal was found by Cheapflights users on 10/20. 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 12/122:20 pm -
2 stops12h 25m
Tue 12/157:30 am -
1 stop9h 10m
Deal found 10/20![WestJet logo]()
$384
This Trip.com deal was found by Cheapflights users on 10/21. 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 11/242:30 pm -
2 stops12h 15m
Mon 11/3010:20 pm -
1 stop18h 20m
Deal found 10/21![WestJet logo]()
$385
This Kiwi.com deal was found by Cheapflights users on 10/20. 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 12/242:30 pm -
2 stops12h 15m
Tue 1/57:30 am -
1 stop9h 10m
Deal found 10/20![WestJet logo]()
$386
Best flights from Seattle to OntarioDiscover carefully curated flight deals from Seattle to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 22, 2026.
Discover carefully curated flight deals from Seattle to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 22, 2026.
This Alaska Airlines deal was found by Cheapflights users on 10/17. 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.
Thu 11/198:19 am -
Nonstop4h 46m
Wed 11/255:15 pm -
Nonstop5h 32m
Deal found 10/17![Alaska Airlines logo]()
$492
This FlightHub deal was found by Cheapflights users on 10/16. 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 1/22:20 pm -
2 stops12h 25m
Thu 3/42:10 pm -
2 stops26h 30m
Deal found 10/16![WestJet logo]()
$500
This Delta deal was found by Cheapflights users on 10/19. 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.
Sat 2/2010:35 am -
1 stop9h 25m
Sat 2/275:15 pm -
1 stop7h 50m
Deal found 10/19![Delta logo]()
$506
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Wed 11/189:18 pm -
2 stops12h 54m
Wed 11/256:10 am -
1 stop10h 30m
Deal found 10/20![Multiple Airlines logo]()
$546
This United Airlines deal was found by Cheapflights users on 10/19. 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 11/1310:56 pm -
1 stop12h 13m
Sat 11/214:46 pm -
1 stop9h 21m
Deal found 10/19![United Airlines logo]()
$650
This Trip.com deal was found by Cheapflights users on 10/19. 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 12/122:20 pm -
1 stop21h 05m
Tue 12/153:25 pm -
1 stop25h 15m
Deal found 10/19![WestJet logo]()
$501
This Alaska Airlines deal was found by Cheapflights users on 10/17. 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.
Thu 11/198:19 am -
Nonstop4h 46m
Sun 11/225:15 pm -
Nonstop5h 32m
Deal found 10/17![Alaska Airlines logo]()
$503
This Alaska Airlines deal was found by Cheapflights users on 10/19. 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.
Thu 12/38:33 am -
Nonstop4h 32m
Thu 12/105:15 pm -
Nonstop5h 41m
Deal found 10/19![Alaska Airlines logo]()
$503
This Air Canada deal was found by Cheapflights users on 10/18. 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 11/57:45 am -
1 stop9h 42m
Sun 11/89:05 pm -
2 stops20h 32m
Deal found 10/18![Air Canada logo]()
$1,178
This KAYAK deal was found by Cheapflights users on 10/19. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/298:31 am -
Nonstop4h 34m
Wed 12/26:10 am -
1 stop10h 30m
Deal found 10/19![Multiple Airlines logo]()
$606
This Mytrip deal was found by Cheapflights users on 10/20. 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 12/42:30 pm -
1 stop12h 05m
Fri 12/119:30 am -
3 stops33h 13m
Deal found 10/20![Multiple Airlines logo]()
$611
This oojo deal was found by Cheapflights users on 10/19. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/192:30 pm -
2 stops30h 10m
Thu 11/265:30 am -
2 stops35h 10m
Deal found 10/19![WestJet logo]()
$615
This Alaska Airlines deal was found by Cheapflights users on 10/20. 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 2/201:45 pm -
1 stop7h 00m
Sat 2/275:15 pm -
Nonstop5h 28m
Deal found 10/20![Alaska Airlines logo]()
$588
This United Airlines deal was found by Cheapflights users on 10/18. 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.
Sun 11/1511:59 pm -
2 stops11h 30m
Sun 11/2210:30 am -
2 stops11h 47m
Deal found 10/18![United Airlines logo]()
$734
This Alaska Airlines deal was found by Cheapflights users on 10/17. 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 11/1711:42 pm -
1 stop8h 08m
Tue 11/245:15 pm -
Nonstop5h 32m
Deal found 10/17![Alaska Airlines logo]()
$588
This Kiwi.com deal was found by Cheapflights users on 10/18. 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.
Tue 11/179:18 pm -
1 stop11h 01m
Tue 11/247:00 am -
2 stops17h 00m
Deal found 10/18![Multiple Airlines logo]()
$656
This United Airlines deal was found by Cheapflights users on 10/20. 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 12/45:35 pm -
2 stops17h 34m
Fri 12/113:10 pm -
1 stop10h 17m
Deal found 10/20![United Airlines logo]()
$744
This Mytrip deal was found by Cheapflights users on 10/18. 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 11/72:20 pm -
1 stop21h 05m
Wed 11/118:00 am -
1 stop8h 40m
Deal found 10/18![Multiple Airlines logo]()
$672
This Alaska Airlines deal was found by Cheapflights users on 10/17. 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 11/178:19 am -
Nonstop4h 46m
Sat 11/285:15 pm -
Nonstop5h 32m
Deal found 10/17![Alaska Airlines logo]()
$623
This United Airlines deal was found by Cheapflights users on 10/18. 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 12/2311:15 pm -
2 stops15h 05m
Mon 1/45:10 am -
2 stops19h 15m
Deal found 10/18![United Airlines logo]()
$809
This Kiwi.com deal was found by Cheapflights users on 10/16. 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.
Fri 12/410:22 am -
1 stop7h 43m
Mon 12/710:30 am -
1 stop14h 16m
Deal found 10/16![Multiple Airlines logo]()
$674
This FlightHub deal was found by Cheapflights users on 10/17. 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 12/122:20 pm -
2 stops30h 20m
Sun 12/275:30 am -
2 stops35h 10m
Deal found 10/17![WestJet logo]()
$842
This United Airlines deal was found by Cheapflights users on 10/17. 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 12/27:00 am -
2 stops24h 07m
Wed 12/97:40 pm -
2 stops25h 48m
Deal found 10/17![United Airlines logo]()
$812
This Kiwi.com deal was found by Cheapflights users on 10/20. 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 11/213:43 pm -
2 stops16h 49m
Sun 11/296:55 pm -
1 stop17h 02m
Deal found 10/20![Multiple Airlines logo]()
$685
This Mytrip deal was found by Cheapflights users on 10/18. 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 11/288:40 am -
1 stop8h 13m
Sat 12/56:05 am -
2 stops11h 32m
Deal found 10/18![Multiple Airlines logo]()
$696
This United Airlines deal was found by Cheapflights users on 10/19. 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.
Mon 11/167:35 pm -
2 stops18h 07m
Thu 11/1912:05 pm -
1 stop14h 02m
Deal found 10/19![United Airlines logo]()
$871
This Bravofly deal was found by Cheapflights users on 10/19. 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 Bravofly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/202:30 pm -
2 stops30h 10m
Sat 1/25:30 am -
2 stops35h 10m
Deal found 10/19![WestJet logo]()
$977
This Mytrip deal was found by Cheapflights users on 10/19. 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.
Thu 12/38:40 am -
1 stop8h 10m
Thu 12/106:05 am -
2 stops15h 17m
Deal found 10/19![Multiple Airlines logo]()
$697
This Kiwi.com deal was found by Cheapflights users on 10/17. 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.
Tue 12/1510:40 pm -
1 stop9h 39m
Wed 12/304:35 pm -
1 stop19h 25m
Deal found 10/17![Multiple Airlines logo]()
$706
This United Airlines deal was found by Cheapflights users on 10/17. 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.
Sat 10/245:00 am -
2 stops9h 16m
Sat 10/316:15 am -
2 stops13h 12m
Deal found 10/17![United Airlines logo]()
$1,045
Last-minute flights from Seattle to OntarioDiscover last-minute flight deals from Seattle to Ontario. Data last updated October 22, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Ontario. Data last updated October 22, 2026 and is based on user searches.
This deal was found by Cheapflights users on 10/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/313:20 pm -
1 stop11h 40m
Thu 11/56:10 am -
1 stop10h 30m
Deal found 10/18![WestJet logo]()
$369
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Tue 11/102:30 pm -
2 stops12h 15m
Thu 1/77:30 am -
1 stop9h 10m
Deal found 10/20![WestJet logo]()
$388
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Tue 11/102:30 pm -
2 stops12h 15m
Fri 1/87:30 am -
1 stop9h 10m
Deal found 10/20![WestJet logo]()
$392
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Tue 11/102:30 pm -
2 stops12h 15m
Tue 1/57:30 am -
1 stop9h 10m
Deal found 10/20![WestJet logo]()
$397
This Justfly.com deal was found by Cheapflights users on 10/21. 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 11/172:30 pm -
2 stops12h 15m
Tue 11/247:30 am -
1 stop9h 10m
Deal found 10/21![WestJet logo]()
$366
This Kiwi.com deal was found by Cheapflights users on 10/17. 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.
Fri 11/202:30 pm -
2 stops12h 15m
Thu 11/267:30 am -
1 stop9h 10m
Deal found 10/17![WestJet logo]()
$393
This Kiwi.com deal was found by Cheapflights users on 10/17. 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.
Fri 11/202:30 pm -
2 stops12h 15m
Fri 11/277:30 am -
1 stop9h 10m
Deal found 10/17![WestJet logo]()
$402
This Kiwi.com deal was found by Cheapflights users on 10/19. 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.
Tue 11/242:30 pm -
2 stops12h 15m
Tue 12/17:30 am -
1 stop9h 10m
Deal found 10/19![WestJet logo]()
$381
This Trip.com deal was found by Cheapflights users on 10/21. 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 11/242:30 pm -
2 stops12h 15m
Mon 11/3010:20 pm -
1 stop18h 20m
Deal found 10/21![WestJet logo]()
$385
This Kiwi.com deal was found by Cheapflights users on 10/19. 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.
Wed 11/252:30 pm -
2 stops12h 15m
Tue 12/17:30 am -
1 stop9h 10m
Deal found 10/19![WestJet logo]()
$390
This Kiwi.com deal was found by Cheapflights users on 10/19. 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 11/282:20 pm -
2 stops12h 25m
Tue 12/17:30 am -
1 stop9h 10m
Deal found 10/19![WestJet logo]()
$383
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 11/282:20 pm -
2 stops12h 25m
Sat 12/59:50 am -
1 stop11h 23m
Deal found 10/21![Multiple Airlines logo]()
$401
One-way flights from Seattle to OntarioSearch for one-way flight options from Seattle to Ontario. Find affordable one-way fares based on user searches. Data last updated October 22, 2026.
Search for one-way flight options from Seattle to Ontario. Find affordable one-way fares based on user searches. Data last updated October 22, 2026.
This FlightHub deal was found by Cheapflights users on 10/20. 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 11/242:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![WestJet logo]()
$170
This Trip.com deal was found by Cheapflights users on 10/21. 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 1/32:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/21![WestJet logo]()
$175
This Kiwi.com deal was found by Cheapflights users on 10/20. 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 12/32:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![WestJet logo]()
$176
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Fri 11/279:53 pm -
1 stop29h 58m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Multiple Airlines logo]()
$177
This Kiwi.com deal was found by Cheapflights users on 10/17. 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.
Mon 12/72:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/17![WestJet logo]()
$183
This FlightHub deal was found by Cheapflights users on 10/21. 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 11/252:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/21![WestJet logo]()
$185
This Kiwi.com deal was found by Cheapflights users on 10/17. 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.
Mon 11/232:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/17![WestJet logo]()
$187
This Kiwi.com deal was found by Cheapflights users on 10/19. 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.
Tue 12/152:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/19![WestJet logo]()
$188
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
Mon 11/309:53 pm -
3 stops59h 57m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/21![Multiple Airlines logo]()
$189
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Mon 1/1110:29 am -
1 stop17h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Multiple Airlines logo]()
$192
This FlightHub deal was found by Cheapflights users on 10/20. 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.
Fri 11/272:30 pm -
2 stops12h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![WestJet logo]()
$193
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Fri 11/209:53 pm -
1 stop29h 58m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Multiple Airlines logo]()
$195
Find flight deals from Seattle to Ontario
Keep the following information in mind while searching for Seattle to Ontario flight deals. Data was last updated October 22, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $366 (Justfly.com) |
One-way from | $170 (FlightHub) |
Popular in | July |
Cheapest in | January |
Average price | $603 |
Good round-trip deal | $572 or less |
Good one-way deal | $310 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Seattle to Ontario 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 October 22, 2026.
Use the filters below to find and compare flights from Seattle to Ontario that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
SeattleToronto
SEA Seattle/Tacoma Intl - YTZ Toronto Island
SEAYTZ
Seattle/Tacoma Intl
Sat 12/5
4:58 pm-3:00 pm
2 stops43h 02m
Toronto Island
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$210
Quickest round-trip
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Tue 12/1
8:33 am-4:05 pm
Nonstop4h 32m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$215
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Wed 11/25
8:31 am-4:05 pm
Nonstop4h 34m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$215
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Wed 11/18
11:15 pm-8:55 am
1 stop6h 40m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$225
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Tue 11/17
10:40 pm-11:09 am
1 stop9h 29m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$225
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Sun 12/27
8:33 am-4:05 pm
Nonstop4h 32m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$226
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Fri 11/20
8:31 am-4:05 pm
Nonstop4h 34m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$226
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Fri 11/27
8:31 am-4:05 pm
Nonstop4h 34m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$226
SeattleToronto
SEA Seattle/Tacoma Intl - YYZ Toronto Pearson Intl
SEAYYZ
Seattle/Tacoma Intl
Sun 1/10
8:29 am-4:05 pm
Nonstop4h 36m
Toronto Pearson Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$226
SeattleToronto
SEA Seattle/Tacoma Intl - YTZ Toronto Island
SEAYTZ
Seattle/Tacoma Intl
Mon 12/14
4:58 pm-12:50 pm
3 stops40h 52m
Toronto Island
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$235
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Seattle to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario from Seattle with our price prediction graph.
SEA-YYZ
SEA-YOW
SEA-YHM
SEA-YXU
SEA-YTZ
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 Seattle to Ontario
SEA-CAON
SEA-YYZ
SEA-YOW
SEA-YHM
SEA-YXU
What is the cheapest month to book a flight from Seattle to Region of Ontario?
Currently, January is the cheapest month in which you can book a flight from Seattle to Region of Ontario (average of $274). Flying from Seattle to Region of Ontario in July is currently the most expensive (average of $604). 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 SEA to ON?
Find hourly flight availability from Seattle to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 22, 2026.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to Region of Ontario as you normally would.
How much does it cost to fly round-trip from Seattle to Region of Ontario?
Airfare is typical for this route at the moment.
Seattle to Region of Ontario flights typically cost between $325 and $650 in November.The cheapest round-trip price found within the last 5 days was $366 on WestJet (Nov 17-Nov 24).
How far ahead should I book a flight from Seattle to Region of Ontario?
The price you pay for your flight from Seattle to Region of Ontario may vary depending on when you book. For the best chance of a lower fare, look to book 64 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
Reviews of airlines servicing Ontario
Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated October 22, 2026.
Read through reviews of airlines operating flights from Seattle to Ontario, such as Alaska Airlines,Delta, andUnited Airlines. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Overall
7.9
Boarding
8.1
Crew
8.5
Comfort
7.8
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Overall
7.9
Boarding
8.1
Crew
8.5
Comfort
7.8
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Overall
7.9
Boarding
8.1
Crew
8.5
Comfort
7.8
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Overall
7.9
Boarding
8.1
Crew
8.5
Comfort
7.8
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Overall
7.9
Boarding
8.1
Crew
8.5
Comfort
7.8
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Food
7.0
Overall
7.9
Boarding
8.1
Crew
8.5
Comfort
7.8
Entertainment
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Related info for your journey
Find useful and relevant information for your journey from Seattle to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Alternative routes for Seattle to Ontario
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Ontario by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Seattle to Ontario by cabin class
Find flights from Seattle to Ontario, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Seattle and Ontario flights
Browse other Seattle and Ontario flight options. Last updated on October 22, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 5 airlines flying from Seattle to Ontario
Discover the top 5 airlines that operate flights from Seattle to Ontario. 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 October 22, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$132 | Average$379 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$132 | Average$534 | FlexibilityNo cancel fee | On-time67% | |
| Cheapest$240 | Average$396 | FlexibilityNo cancel fee | On-time60% | |
| Cheapest$245 | Average$520 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$277 | Average$599 | FlexibilityNo cancel fee | On-time69% |