Cheapest return flights from Seattle to Bangkok in September from $660

AirHint found the following cheapest return flights from Seattle (SEA) to Bangkok (BKK) in September 2025 (see full year).

Return flights

03 Sep - 17 Sep Philippine Airlines
07 Sep - 21 Sep Philippine Airlines
03 Sep - 10 Sep Philippine Airlines
11 Sep - 16 Sep Asiana Airlines
01 Sep - 31 Oct Asiana Airlines
04 Sep - 11 Sep Asiana Airlines
18 Sep - 25 Sep Asiana Airlines
03 Sep - 24 Sep Philippine Airlines
13 Sep - 27 Sep STARLUX Airlines
30 Sep - 08 Oct STARLUX Airlines

Also check the deals for one-way flights from Seattle to Bangkok in September.

Skyscanner

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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