Cheapest return flights from Seattle to Barcelona in September from 416€

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

Return flights

21 Sep - 29 Sep Lufthansa
26 Sep - 03 Oct Lufthansa
27 Sep - 07 Oct United
16 Sep - 30 Sep United
26 Sep - 05 Oct Lufthansa
16 Sep - 27 Sep United
13 Sep - 21 Sep United
13 Sep - 20 Sep United
22 Sep - 26 Sep Icelandair
19 Sep - 11 Oct Frontier Airlines
10 Sep - 23 Sep WestJet
10 Sep - 18 Sep WestJet
11 Sep - 18 Sep WestJet

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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