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

Return flights

09 Dec - 16 Dec	Air Canada
02 Dec - 16 Dec	Air Canada
04 Dec - 07 Dec	Scandinavian Airlines
01 Dec - 09 Dec	Delta
02 Dec - 09 Dec	Delta
03 Dec - 10 Dec	British Airways	direct
02 Dec - 16 Dec	British Airways	direct
08 Dec - 15 Dec	British Airways	direct
05 Dec - 19 Dec	TAP
01 Dec - 15 Dec	British Airways	direct
30 Dec - 30 Jan	Air Canada
26 Dec - 09 Jan	Scandinavian Airlines
23 Dec - 09 Jan	Air Canada
12 Dec - 12 Jan	SWISS
25 Dec - 10 Jan	United
16 Dec - 06 Jan	British Airways
15 Dec - 01 Jan	Delta
14 Dec - 01 Jan	Delta
16 Dec - 06 Jan	United	direct
14 Dec - 04 Jan	British Airways	direct

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 401€

Return flights