Cheapest return flights from Seattle to London in April from $518

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

Return flights

14 Apr - 09 May Icelandair
20 Apr - 07 May Icelandair
23 Apr - 27 Apr Icelandair
05 Apr - 25 Apr Icelandair
23 Apr - 03 May Icelandair
06 Apr - 07 May Icelandair
04 Apr - 11 Apr Icelandair
01 Apr - 11 Apr Icelandair
01 Apr - 14 Apr Icelandair
09 Apr - 02 May Icelandair
02 Apr - 25 Apr Icelandair
10 Apr - 21 Apr Icelandair

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

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