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

Return flights

14 Sep - 21 Sep	Air India
06 Sep - 22 Sep	Air India
08 Sep - 22 Sep	Air India
08 Sep - 15 Sep	Air India
02 Sep - 09 Sep	Air India
03 Sep - 10 Sep	Air India
17 Sep - 24 Sep	Air India
04 Sep - 11 Sep	Air India
09 Sep - 23 Sep	Air India
02 Sep - 16 Sep	Air India
26 Sep - 06 Oct	Air India
14 Sep - 07 Oct	Air India
03 Sep - 03 Oct	Air India
22 Sep - 10 Oct	Singapore Airlines
29 Sep - 09 Oct	Singapore Airlines
30 Sep - 07 Oct	Singapore Airlines
29 Sep - 10 Oct	Singapore Airlines
29 Sep - 07 Oct	Singapore Airlines
30 Sep - 14 Oct	Singapore Airlines
17 Sep - 01 Oct	Singapore Airlines

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

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 San Francisco to Bangkok in September from 539€

Return flights