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

Return flights

12 Dec - 19 Jan	Frontier Airlines
10 Dec - 14 Dec	Alaska Airlines
09 Dec - 16 Dec	Alaska Airlines
13 Dec - 12 Jan	Icelandair
29 Dec - 09 Jan	Frontier Airlines
29 Dec - 08 Jan	Frontier Airlines
10 Dec - 06 Jan	Lufthansa
12 Dec - 29 Dec	Frontier Airlines
12 Dec - 31 Dec	Frontier Airlines
10 Dec - 15 Dec	Icelandair
15 Dec - 06 Jan	Alaska Airlines
13 Dec - 21 Dec	Frontier Airlines
12 Dec - 23 Dec	Frontier Airlines
20 Dec - 20 Jan	Frontier Airlines
12 Dec - 26 Dec	Frontier Airlines
31 Dec - 07 Jan	Alaska Airlines
12 Dec - 21 Dec	Frontier Airlines
17 Dec - 07 Jan	WestJet
10 Dec - 23 Dec	Alaska Airlines
25 Dec - 10 Jan	Lufthansa

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 $835

Return flights