Earn point on your loyalty program!arrow arc left

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

Know your dates, get live prices in seconds
airplane logo

pin logo

calendar
Departure
calendar backward
Return
airplane logo
1 Adults (11+)
0 Children (2~11)
0 Infants (0~2)
Save up to 31%
Book Flight + Hotel at the same time

How to find the cheapest flight from Boston (BOS) to Seattle (BFI)

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.
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.

Cheap flights from Boston to Seattle in May , June 2026

31 May - 12 Jun $ 859.00
BOS
Boston
Allegiant Air
2 STOPS
BFI
Seattle
BFI
Seattle
Allegiant Air
2 STOPS
BOS
Boston
Pick dates
31 May - 12 Jun $ 882.00
BOS
Boston
Allegiant Air
2 STOPS
BFI
Seattle
BFI
Seattle
Allegiant Air
2 STOPS
BOS
Boston
Pick dates
24 May - 12 Jun $ 885.00
BOS
Boston
Allegiant Air
2 STOPS
BFI
Seattle
BFI
Seattle
Allegiant Air
2 STOPS
BOS
Boston
Pick dates

Last minute flights from Boston to Seattle

21 May - 01 Jun $ 1,168.00
BOS
Boston
Sun Country Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Sun Country Airlines
2 STOPS
BOS
Boston
Pick dates
24 May - 01 Jun $ 1,173.00
BOS
Boston
Sun Country Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Sun Country Airlines
2 STOPS
BOS
Boston
Pick dates
21 May - 01 Jun $ 1,190.00
BOS
Boston
Sun Country Airlines
2 STOPS
BFI
Seattle
BFI
Seattle
Sun Country Airlines
2 STOPS
BOS
Boston
Pick dates

One-way flights to Seattle from Boston

9:23 AM - 6:45 PM
Air Excursions
2 Stops
37h 12m
BOS - BFI
$ 429
Kiwi
Pick dates
9:23 AM - 4:05 PM
Air Excursions
2 Stops
34h 32m
BOS - BFI
$ 451
Kiwi
Pick dates
9:23 AM - 4:05 PM
Air Excursions
2 Stops
34h 32m
BOS - BFI
$ 455
Kiwi
Pick dates

How to find the cheapest flight from Boston (BOS) to Seattle (BFI)

Related info for your journey
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.
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.