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

Return flights

22 Sep - 29 Sep	United
25 Sep - 02 Oct	United
03 Sep - 14 Sep	Spirit Airlines
28 Sep - 05 Oct	United
10 Sep - 17 Sep	United
18 Sep - 22 Sep	Air Canada
10 Sep - 18 Sep	Iberia
16 Sep - 23 Sep	United
10 Sep - 24 Sep	British Airways
06 Sep - 17 Sep	Hawaiian Airlines
07 Sep - 14 Sep	United
18 Sep - 28 Sep	Air Canada

Also check the deals for one-way flights from San Diego 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 Diego to Barcelona in September from $618

Return flights