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

Return flights

08 Dec - 15 Dec	jetBlue
09 Dec - 16 Dec	Frontier Airlines
13 Dec - 08 Jan	Alaska Airlines
28 Dec - 17 Jan	Sun Country Airlines
03 Dec - 17 Dec	Spirit Airlines
29 Dec - 24 Jan	Sun Country Airlines
30 Dec - 08 Jan	Sun Country Airlines
29 Dec - 12 Jan	SWISS
13 Dec - 26 Dec	Alaska Airlines
28 Dec - 08 Jan	Sun Country Airlines
17 Dec - 10 Jan	Icelandair
16 Dec - 01 Jan	Spirit Airlines
17 Dec - 02 Jan	Icelandair
12 Dec - 20 Dec	Lufthansa
22 Dec - 02 Jan	Icelandair

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.

Book a cheap hotel in London

Cheap car rent in London

Cheapest return flights from San Diego to London in December from $699

Return flights