Cheapest return flights from Seattle to London in December from $553

Best time to book flights for Seattle (SEA) to London (LHR) flights at AirHint

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

Return flights

10 Dec - 17 Dec Icelandair
11 Dec - 25 Dec Icelandair
08 Dec - 22 Dec Icelandair
09 Dec - 30 Dec Lufthansa
10 Dec - 30 Dec Lufthansa
08 Dec - 15 Dec Icelandair
10 Dec - 17 Dec Air France direct
28 Dec - 12 Jan Air Canada
08 Dec - 22 Dec Air France direct
08 Dec - 15 Dec British Airways direct
09 Dec - 30 Dec Air France direct
23 Dec - 02 Jan Lufthansa
28 Dec - 12 Jan British Airways direct
25 Dec - 03 Jan Lufthansa
21 Dec - 03 Jan Lufthansa
20 Dec - 03 Jan Air Canada
23 Dec - 02 Jan Air France direct
28 Dec - 04 Jan Icelandair
26 Dec - 03 Jan Icelandair
25 Dec - 03 Jan Air France direct

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

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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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