AirHint found the following cheapest return flights from Seattle (SEA) to Barcelona (BCN) in May 2026 (see full year).

Return flights

07 May - 15 May	Icelandair
02 May - 10 May	Icelandair
01 May - 13 May	Icelandair
02 May - 09 May	Icelandair
07 May - 11 May	Icelandair
09 May - 20 May	Icelandair
09 May - 16 May	Icelandair
09 May - 17 May	Icelandair
09 May - 21 May	Condor
05 May - 26 May	Icelandair
18 May - 08 Jun	Condor
30 May - 07 Jun	Condor
23 May - 07 Jun	Condor
31 May - 07 Jun	Icelandair
23 May - 07 Jun	Air France	direct

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

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 Seattle to Barcelona in May from $398

Return flights