AirHint found the following cheapest return flights from London (LHR) to San Francisco (SFO) in April 2026 (see full year).

Return flights

22 Apr - 27 Apr	SWISS
11 Apr - 24 Apr	Aer Lingus
18 Apr - 02 May	Aer Lingus
30 Apr - 12 May	Aer Lingus
30 Apr - 07 May	Aer Lingus
18 Apr - 25 Apr	Aer Lingus
25 Apr - 02 May	Aer Lingus
17 Apr - 25 Apr	SWISS
30 Apr - 04 May	SWISS
23 Apr - 30 Apr	SWISS
19 Apr - 26 Apr	Aer Lingus
24 Apr - 25 Apr	Aer Lingus
14 Apr - 24 Apr	SWISS
12 Apr - 22 Apr	SWISS
29 Apr - 06 May	SWISS
13 Apr - 19 Apr	Lufthansa
26 Apr - 03 May	Aer Lingus
27 Apr - 01 May	Lufthansa
27 Apr - 04 May	Air Canada
27 Apr - 01 May	British Airways	direct

Also check the deals for one-way flights from London to San Francisco in April.

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 Francisco in April from 403€

Return flights