AirHint found the following cheapest return flights from Washington (IAD) to Barcelona (BCN) in August 2025 (see full year).

Return flights

30 Aug - 03 Sep	Frontier Airlines
30 Aug - 05 Sep	Frontier Airlines
30 Aug - 02 Sep	Frontier Airlines
31 Aug - 04 Sep	TAP
31 Aug - 06 Sep	Lufthansa
31 Aug - 07 Sep	United	direct
31 Aug - 06 Sep	Lufthansa	direct
30 Aug - 05 Sep	Lufthansa	direct
31 Aug - 04 Sep	Lufthansa	direct
30 Aug - 02 Sep	Lufthansa	direct

Also check the deals for one-way flights from Washington to Barcelona in August.

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 Washington to Barcelona in August from $716

Return flights