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

Return flights

06 Dec - 16 Dec	Air Canada
03 Dec - 16 Dec	Air Canada
08 Dec - 16 Dec	Air Canada
03 Dec - 09 Dec	Air Canada
02 Dec - 16 Dec	Air Canada
01 Dec - 16 Dec	Air Canada
07 Dec - 16 Dec	Air Canada
03 Dec - 26 Dec	TAP
02 Dec - 09 Dec	Delta
02 Dec - 07 Dec	Air Canada
10 Dec - 06 Jan	Air Canada
16 Dec - 06 Jan	Air Canada
28 Dec - 06 Jan	Scandinavian Airlines
31 Dec - 09 Jan	Air Canada
23 Dec - 13 Jan	Air Canada
24 Dec - 14 Jan	Air Canada
23 Dec - 08 Jan	Air Canada
23 Dec - 09 Jan	Air Canada
26 Dec - 10 Jan	Scandinavian Airlines
07 Dec - 04 Jan	SWISS

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

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 San Francisco to London in December from $460

Return flights