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

Return flights

01 Dec - 09 Dec	TAP
01 Dec - 07 Dec	TAP
01 Dec - 11 Dec	Air Canada
01 Dec - 14 Dec	TAP
05 Dec - 12 Dec	TAP
05 Dec - 14 Dec	TAP
07 Dec - 15 Dec	Air Canada
09 Dec - 13 Jan	British Airways
03 Dec - 11 Dec	Air Canada
11 Dec - 14 Jan	Frontier Airlines
05 Dec - 07 Dec	TAP
10 Dec - 14 Jan	Frontier Airlines
12 Dec - 14 Jan	Frontier Airlines
04 Dec - 07 Dec	Scandinavian Airlines
13 Dec - 11 Jan	Frontier Airlines
30 Dec - 18 Jan	SWISS
15 Dec - 09 Jan	Hawaiian Airlines
12 Dec - 06 Jan	Frontier Airlines
13 Dec - 16 Jan	Icelandair
15 Dec - 06 Jan	Hawaiian 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 $526

Return flights