Cheapest return flights from Seattle to Barcelona in September from $661

Best time to book flights for Seattle (SEA) to Barcelona (BCN) flights at AirHint

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

Return flights

09 Sep - 18 Sep Turkish Airlines
16 Sep - 22 Sep Turkish Airlines
09 Sep - 17 Sep Turkish Airlines
16 Sep - 07 Oct Turkish Airlines
24 Sep - 06 Oct Turkish Airlines
11 Sep - 18 Sep Turkish Airlines
07 Sep - 11 Sep Icelandair
19 Sep - 19 Oct Aer Lingus

Also check the deals for one-way flights from Seattle to Barcelona in September.

Skyscanner

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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