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Cheap flights from Boston (BOS) to Seattle (BFI)

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0 Children (2~11)
0 Infants (0~2)
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How to find the cheapest flight from Boston (BOS) to Seattle (BFI)

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

18 Dec - 16 Jan $ 1,140.00
BOS
Boston
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
BOS
Boston
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18 Dec - 17 Jan $ 1,151.00
BOS
Boston
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
BOS
Boston
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18 Dec - 12 Jan $ 1,176.00
BOS
Boston
Spirit Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Spirit Airlines
3 STOPS
BOS
Boston
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Last minute flights from Boston to Seattle

18 Dec - 02 Jan $ 1,299.00
BOS
Boston
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
BOS
Boston
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18 Dec - 02 Jan $ 1,430.00
BOS
Boston
Spirit Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Spirit Airlines
3 STOPS
BOS
Boston
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18 Dec - 01 Jan $ 1,441.00
BOS
Boston
Frontier Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
BOS
Boston
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One-way flights to Seattle from Boston

11:49 AM - 5:35 AM
Air Excursions
2 Stops
21h 36m
BOS - BFI
$ 698
Kiwi
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6:10 AM - 6:45 AM
Air Excursions
3 Stops
28h 25m
BOS - BFI
$ 823
Kiwi
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12:45 PM - 2:45 PM
Air Excursions
3 Stops
29h 50m
BOS - BFI
$ 864
Kiwi
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How to find the cheapest flight from Boston (BOS) to Seattle (BFI)

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