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Cheap flights from Philadelphia (PHL) to Seattle (BFI)

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How to find the cheapest flight from Philadelphia (PHL) to Seattle (BFI)

How to find the cheapest flight from Philadelphia (PHL) to Seattle (BFI)
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How to find the cheapest flight from Philadelphia (PHL) to Seattle (BFI)
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How to find the cheapest flight from Philadelphia (PHL) to Seattle (BFI)
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Cheap flights from Philadelphia to Seattle in September , October 2026

30 Sep - 20 Oct $ 778.00
PHL
Philadelphia
Frontier Airlines
3 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
PHL
Philadelphia
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30 Sep - 13 Oct $ 816.00
PHL
Philadelphia
Frontier Airlines
3 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
PHL
Philadelphia
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30 Sep - 20 Oct $ 816.00
PHL
Philadelphia
Frontier Airlines
3 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
2 STOPS
PHL
Philadelphia
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Last minute flights from Philadelphia to Seattle

17 Sep - 02 Oct $ 888.00
PHL
Philadelphia
Frontier Airlines
3 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
PHL
Philadelphia
Pick dates
23 Sep - 02 Oct $ 912.00
PHL
Philadelphia
Frontier Airlines
3 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
PHL
Philadelphia
Pick dates
16 Sep - 02 Oct $ 917.00
PHL
Philadelphia
Frontier Airlines
3 STOPS
BFI
Seattle
BFI
Seattle
Frontier Airlines
3 STOPS
PHL
Philadelphia
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One-way flights to Seattle from Philadelphia

12:40 PM - 6:45 PM
Air Excursions
3 Stops
33h 55m
PHL - BFI
$ 434
Kiwi
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5:32 PM - 6:45 PM
Air Excursions
3 Stops
29h 3m
PHL - BFI
$ 435
Kiwi
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5:32 PM - 4:05 PM
Air Excursions
3 Stops
26h 23m
PHL - BFI
$ 474
Kiwi
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How to find the cheapest flight from Philadelphia (PHL) to Seattle (BFI)

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