Cheapest one-way flights from Seattle to Barcelona in September from 229€

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

One-Way flights

23 Sep WestJet
30 Sep WestJet
08 Sep Hawaiian Airlines
09 Sep Hawaiian Airlines
25 Sep Frontier Airlines
24 Sep Hawaiian Airlines
26 Sep Frontier Airlines
15 Sep Hawaiian Airlines
14 Sep Frontier Airlines
03 Sep Alaska Airlines

Also check the deals for return 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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