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

Return flights

01 Dec - 10 Dec	TAP
05 Dec - 10 Dec	TAP
05 Dec - 11 Dec	TAP
10 Dec - 09 Jan	Scandinavian Airlines
08 Dec - 14 Dec	TAP
06 Dec - 15 Dec	TAP
05 Dec - 14 Dec	TAP
01 Dec - 14 Dec	TAP
01 Dec - 08 Dec	TAP
03 Dec - 08 Dec	TAP
02 Dec - 16 Dec	Virgin Atlantic
31 Dec - 15 Jan	Virgin Atlantic
29 Dec - 13 Jan	Virgin Atlantic
10 Dec - 12 Jan	Virgin Atlantic
31 Dec - 12 Jan	Virgin Atlantic
09 Dec - 20 Jan	Delta
29 Dec - 22 Jan	SWISS
28 Dec - 14 Jan	Scandinavian Airlines
28 Dec - 17 Jan	Scandinavian Airlines
28 Dec - 09 Jan	Scandinavian Airlines

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 458€

Return flights