Ontario → Seattle flights
Ontario (ONT)→Seattle (BFI, SEA)
from$99
Last observed price · Last checked: 11 Aug 2026 · Price may change
Selected search
Last checked: 11 Aug 2026 · Price may change
$99
Sun 25 Oct 2026 → Thu 29 Oct 2026
Frontier AirlinesNon-stop4 nights
CheapestLast checked: 11 Aug 2026 · Price may change
$99 lowest$220 average2h 56m fastest
Tickets found in the last 7 days
The lowest fares our queries caught, cheapest first.
FA$99Cheapest25 Oct 2026 → 29 Oct 2026Frontier Airlines · Non-stop · 17:05Last checked: 11 Aug 2026 · Price may change4 nightsView ticket →FA$10516 Oct 2026 → 18 Oct 2026Frontier Airlines · Non-stop · 17:05Last checked: 11 Aug 2026 · Price may change2 nightsView ticket →FA$11322 Oct 2026 → 5 Nov 2026Frontier Airlines · Non-stop · 17:05Last checked: 11 Aug 2026 · Price may change14 nightsView ticket →FA$20511 Nov 2026 → 26 Nov 2026Frontier Airlines · Non-stop · 17:05Last checked: 11 Aug 2026 · Price may change15 nightsView ticket →AA$25719 Aug 2026Alaska Airlines · 1 stop · 07:12Last checked: 11 Aug 2026 · Price may changeOne wayView ticket →FA$27315 Aug 2026 → 16 Aug 2026Frontier Airlines · 1 stop · 06:00Last checked: 11 Aug 2026 · Price may change1 nightView ticket →FA$27512 Aug 2026 → 17 Aug 2026Frontier Airlines · Non-stop · 16:09Last checked: 11 Aug 2026 · Price may change5 nightsView ticket →FA$28114 Aug 2026 → 18 Aug 2026Frontier Airlines · Non-stop · 16:49Last checked: 11 Aug 2026 · Price may change4 nightsView ticket →
Price calendar
Only prices we actually observed are shown, and days with no data are left empty. Click an empty day and we will search it for you.
October 2026
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Sun
Observed priceLowestno price observedLast checked: 11 Aug 2026
Ontario → SeattleSun 25 Oct 2026 · $99
Find flightsRoute facts
Direct flights
Non-stop
ONT - BFI, 2h 56m
Airlines seen
2
Alaska Airlines, Frontier Airlines
Cheapest month
October 2026
$99
Average observed
$220
Typical duration
2h 56m
Alternative airports
1
SEA
Frequently asked
Are there direct flights from Ontario to Seattle?+−
Yes. We have seen non-stop flights on this route, flown by Alaska Airlines.
How much is a flight from Ontario to Seattle?+−
The lowest fare we have observed is $99, found on 11 Aug 2026. Prices move, so read it as a floor rather than a quote.
Which airlines fly from Ontario to Seattle?+−
These are the carriers we have seen on the route: Alaska Airlines, Frontier Airlines.
When is the cheapest month to fly from Ontario to Seattle?+−
In our observations October 2026 is the cheapest month so far, at $99.
Similar routes
Last checked: 11 Aug 2026