Cheapest return flights from Seattle to London in December from $508

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

Return flights

01 Dec - 08 Dec Air France
09 Dec - 16 Dec British Airways
11 Dec - 17 Dec Air France direct
01 Dec - 08 Dec Virgin Atlantic direct
04 Dec - 11 Dec British Airways
11 Dec - 06 Jan Air France
26 Dec - 12 Jan Icelandair
26 Dec - 12 Jan British Airways direct
14 Dec - 21 Dec United
21 Dec - 31 Dec Icelandair
28 Dec - 05 Jan Air Canada
23 Dec - 02 Jan Air Canada
24 Dec - 31 Dec United
24 Dec - 31 Dec British Airways direct
28 Dec - 04 Jan Lufthansa
26 Dec - 02 Jan Lufthansa
11 Dec - 06 Jan British Airways direct
23 Dec - 02 Jan Air France direct
26 Dec - 02 Jan Air France direct
21 Dec - 31 Dec British Airways 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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