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

Return flights

24 Sep - 28 Sep	KLM
25 Sep - 28 Sep	KLM
25 Sep - 01 Oct	Delta
26 Sep - 01 Oct	Delta
27 Sep - 15 Oct	Delta
25 Sep - 29 Sep	Delta
24 Sep - 29 Sep	Delta
23 Sep - 30 Sep	KLM
24 Sep - 30 Sep	KLM
23 Sep - 28 Oct	KLM
26 Sep - 03 Oct	Delta
24 Sep - 08 Oct	Delta
29 Sep - 15 Oct	Delta
23 Sep - 29 Sep	Air Canada
19 Sep - 22 Sep	ITA Airways
25 Sep - 29 Sep	Iberia For Level	direct
25 Sep - 28 Sep	Iberia For Level	direct
25 Sep - 10 Oct	Delta
25 Sep - 01 Oct	Iberia For Level	direct
28 Sep - 15 Oct	Delta

Also check the deals for one-way flights from Barcelona to Boston 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 Barcelona to Boston in September from $441

Return flights