AirHint found the following cheapest return flights from St. Louis (STL) to Barcelona (BCN) in October 2025 (see full year).

Return flights

01 Oct - 08 Oct	Air Canada
15 Oct - 22 Oct	United
08 Oct - 15 Oct	United
02 Oct - 09 Oct	United
30 Oct - 06 Nov	United
16 Oct - 23 Oct	Air Canada
24 Oct - 31 Oct	United
18 Oct - 25 Oct	United
27 Oct - 03 Nov	United
21 Oct - 28 Oct	United
06 Oct - 13 Oct	United
12 Oct - 19 Oct	United

Also check the deals for one-way flights from St. Louis to Barcelona in October.

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 St. Louis to Barcelona in October from 490€

Return flights