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

Return flights

22 Sep - 30 Sep	Air Canada
23 Sep - 02 Oct	Air Canada
22 Sep - 08 Oct	United	direct
21 Sep - 08 Oct	United
30 Sep - 08 Oct	United
22 Sep - 01 Oct	United	direct
23 Sep - 07 Oct	Air Canada
24 Sep - 07 Oct	Air Canada
22 Sep - 07 Oct	Air Canada
21 Sep - 01 Oct	United
29 Sep - 16 Oct	United
23 Sep - 30 Sep	United
21 Sep - 30 Sep	United
07 Sep - 27 Sep	Iberia For Level	direct
13 Sep - 27 Sep	Iberia For Level	direct
21 Sep - 27 Sep	Iberia For Level	direct
16 Sep - 24 Sep	Iberia
16 Sep - 23 Sep	Iberia
22 Sep - 29 Sep	Lufthansa
06 Sep - 27 Sep	Iberia For Level	direct

Also check the deals for one-way flights from San Francisco to Barcelona 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 Barcelona in September from 388€

Return flights