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

Return flights

23 Oct - 10 Nov	Singapore Airlines
30 Oct - 13 Nov	Singapore Airlines
31 Oct - 15 Nov	Singapore Airlines
12 Oct - 26 Oct	Philippine Airlines
05 Oct - 19 Oct	Philippine Airlines
01 Oct - 22 Oct	Philippine Airlines
01 Oct - 24 Oct	Philippine Airlines
17 Oct - 23 Nov	Philippine Airlines
14 Oct - 04 Nov	STARLUX Airlines
17 Oct - 24 Oct	Philippine Airlines
01 Oct - 16 Oct	Delta

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

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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Cheapest return flights from Seattle to Bangkok in October from $606

Return flights