AirHint found the following cheapest return flights from London (LCY) to San Jose (SJO) in December 2025 (see full year).

Return flights

09 Dec - 20 Jan	KLM
04 Dec - 23 Dec	SWISS
04 Dec - 17 Dec	SWISS
09 Dec - 15 Jan	Delta
04 Dec - 09 Dec	SWISS
02 Dec - 16 Dec	SWISS
08 Dec - 18 Dec	SWISS
04 Dec - 18 Dec	SWISS
30 Dec - 20 Jan	KLM
04 Dec - 11 Dec	SWISS
23 Dec - 30 Dec	SWISS
05 Dec - 17 Dec	KLM
03 Dec - 11 Dec	Iberia
30 Dec - 13 Jan	SWISS
01 Dec - 01 Jan	SWISS
30 Dec - 29 Jan	SWISS
23 Dec - 22 Jan	SWISS
31 Dec - 12 Jan	KLM
16 Dec - 15 Jan	SWISS
15 Dec - 15 Jan	SWISS

Also check the deals for one-way flights from London to San Jose 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 London to San Jose in December from $828

Return flights