Cheapest return flights from Seattle to London in May from 509€

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

Return flights

09 May - 23 May Scandinavian Airlines
04 May - 11 May Icelandair
01 May - 08 May Icelandair
01 May - 12 May Delta
04 May - 30 May Icelandair
08 May - 30 May Icelandair
07 May - 30 May Icelandair
01 May - 08 May Air France direct
15 May - 22 May Icelandair
15 May - 22 May Finnair direct
22 May - 01 Jun Scandinavian Airlines
31 May - 20 Jun Scandinavian Airlines
21 May - 13 Jun Finnair
21 May - 13 Jun British Airways direct
31 May - 20 Jun British Airways direct
22 May - 01 Jun British Airways direct

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

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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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