AirHint found the following cheapest return flights from Seattle (SEA) to London (LGW) in October 2025 (see full year).

Return flights

31 Oct - 02 Nov	Icelandair
20 Oct - 31 Oct	Icelandair
22 Oct - 15 Nov	Icelandair
20 Oct - 15 Nov	Icelandair
26 Oct - 22 Nov	Icelandair
11 Oct - 06 Nov	Icelandair
08 Oct - 24 Oct	Icelandair
14 Oct - 08 Nov	Icelandair
15 Oct - 08 Nov	Icelandair
28 Oct - 22 Nov	Icelandair
17 Oct - 04 Nov	Icelandair
13 Oct - 08 Nov	Icelandair
03 Oct - 07 Oct	Icelandair
08 Oct - 15 Oct	Icelandair
20 Oct - 26 Oct	Icelandair
14 Oct - 26 Oct	Icelandair
21 Oct - 28 Oct	Icelandair
20 Oct - 28 Oct	Icelandair
09 Oct - 30 Oct	Icelandair
22 Oct - 30 Oct	Icelandair

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

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 London in October from $476

Return flights