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Cheap flights from Ontario (ONT) to Seattle (BFI)

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How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)

How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)
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How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)
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How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)
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Cheap flights from Ontario to Seattle in December 2025 , January 2026

30 Dec - 18 Jan $ 915.00
ONT
Ontario
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
ONT
Ontario
Pick dates
30 Dec - 16 Jan $ 915.00
ONT
Ontario
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
ONT
Ontario
Pick dates
30 Dec - 29 Jan $ 921.00
ONT
Ontario
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
ONT
Ontario
Pick dates

Last minute flights from Ontario to Seattle

30 Dec - 01 Jan $ 994.00
ONT
Ontario
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
ONT
Ontario
Pick dates
28 Dec - 01 Jan $ 1,026.00
ONT
Ontario
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
ONT
Ontario
Pick dates
23 Dec - 01 Jan $ 1,036.00
ONT
Ontario
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
ONT
Ontario
Pick dates

One-way flights to Seattle from Ontario

6:00 AM - 4:05 PM
Air Excursions
2 Stops
10h 55m
ONT - BFI
$ 524
Kiwi
Pick dates
6:00 AM - 5:45 PM
Air Excursions
2 Stops
12h 35m
ONT - BFI
$ 557
Kiwi
Pick dates
6:00 AM - 4:05 PM
Air Excursions
2 Stops
10h 55m
ONT - BFI
$ 558
Kiwi
Pick dates

How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)

Related info for your journey
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How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.
How to find the cheapest flight from Ontario (ONT) to Seattle (BFI)
Some placeholder content for the first accordion panel. This panel is shown by default, thanks to the .show class.