AirHint found the following cheapest return flights from Seattle (SEA) to Bangkok (BKK) in April 2026 (see full year).

Return flights

03 Apr - 26 Apr	Asiana Airlines
20 Apr - 23 Apr	Asiana Airlines
25 Apr - 08 May	Asiana Airlines
27 Apr - 08 May	Asiana Airlines
22 Apr - 01 May	Asiana Airlines
20 Apr - 03 May	Asiana Airlines
10 Apr - 20 Apr	Asiana Airlines
07 Apr - 17 Apr	Asiana Airlines
12 Apr - 27 Apr	Korean Air
06 Apr - 19 Apr	Cathay Pacific
06 Apr - 20 Apr	Cathay Pacific
01 Apr - 16 Apr	Cathay Pacific
09 Apr - 23 Apr	Cathay Pacific
05 Apr - 20 Apr	Philippine Airlines

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

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 April from 559€

Return flights