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

Return flights

30 Sep - 07 Oct	United
21 Sep - 30 Sep	United
24 Sep - 01 Oct	United
10 Sep - 24 Sep	Air Canada
02 Sep - 23 Sep	Hawaiian Airlines
09 Sep - 16 Sep	United
03 Sep - 10 Sep	United
10 Sep - 17 Sep	British Airways
03 Sep - 22 Sep	Air Canada
15 Sep - 22 Sep	United
02 Sep - 22 Sep	Lufthansa
25 Sep - 30 Sep	British Airways
18 Sep - 01 Oct	United

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 483€

Return flights