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

Return flights

09 Sep - 21 Sep	China Southern
05 Sep - 14 Sep	China Southern
05 Sep - 15 Sep	China Southern
05 Sep - 08 Sep	China Southern
22 Sep - 20 Oct	China Eastern
22 Sep - 23 Oct	China Eastern
22 Sep - 24 Oct	China Eastern
22 Sep - 25 Oct	China Eastern
22 Sep - 22 Oct	China Eastern
06 Sep - 03 Oct	China Eastern
04 Sep - 22 Sep	China Eastern
22 Sep - 21 Oct	China Eastern
19 Sep - 30 Sep	China Southern
19 Sep - 17 Oct	China Southern
09 Sep - 02 Oct	Philippine Airlines
18 Sep - 16 Oct	China Eastern
10 Sep - 17 Sep	China Southern
19 Sep - 26 Sep	China Southern
12 Sep - 18 Sep	China Southern
09 Sep - 16 Sep	China Southern

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 $440

Return flights