Cheapest return flights from Seattle to London in December from 402€

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

Return flights

28 Dec - 13 Jan Lufthansa
02 Dec - 10 Dec Lufthansa
03 Dec - 14 Jan Delta
02 Dec - 10 Dec Virgin Atlantic direct
03 Dec - 10 Dec Icelandair
01 Dec - 08 Dec Icelandair
01 Dec - 07 Dec Aer Lingus
16 Dec - 23 Dec Air France direct
01 Dec - 08 Dec Virgin Atlantic direct
08 Dec - 15 Dec Icelandair
26 Dec - 12 Jan Icelandair
28 Dec - 13 Jan British Airways direct
03 Dec - 10 Dec British Airways direct
26 Dec - 15 Jan Icelandair
26 Dec - 15 Jan British Airways direct
01 Dec - 31 Dec Delta direct
26 Dec - 02 Jan Lufthansa
17 Dec - 02 Jan Air Canada
17 Dec - 04 Jan Delta
26 Dec - 02 Jan British Airways direct

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

Skyscanner

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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