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

Return flights

09 Dec - 16 Dec	Air Canada
02 Dec - 09 Dec	Air Canada
03 Dec - 17 Dec	Air Canada
02 Dec - 09 Dec	American Airlines	direct
10 Dec - 17 Dec	United
28 Dec - 09 Jan	Delta
28 Dec - 11 Jan	United
05 Dec - 12 Dec	British Airways
09 Dec - 16 Dec	Finnair	direct
13 Dec - 18 Dec	Frontier Airlines
04 Dec - 14 Dec	United
12 Dec - 20 Dec	British Airways
28 Dec - 09 Jan	American Airlines	direct
30 Dec - 06 Jan	Lufthansa
28 Dec - 11 Jan	British Airways	direct
27 Dec - 10 Jan	Delta
27 Dec - 11 Jan	Delta
27 Dec - 11 Jan	Finnair	direct
27 Dec - 10 Jan	British Airways	direct
17 Dec - 07 Jan	Hawaiian Airlines

Also check the deals for one-way flights from San Diego 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 Diego to London in December from $654

Return flights