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

Return flights

19 May - 02 Jun	SWISS
12 May - 19 May	TAP
19 May - 26 May	Alaska Airlines
08 May - 16 May	SWISS
01 May - 15 May	TAP
28 May - 12 Jun	TAP
29 May - 05 Jun	Flair Airlines
24 May - 07 Jun	Alaska Airlines
02 May - 17 May	Alaska Airlines
23 May - 06 Jun	SWISS
26 May - 15 Jun	TAP
27 May - 12 Jun	jetBlue
21 May - 13 Jun	Scandinavian Airlines
13 May - 06 Jun	Icelandair
31 May - 08 Jun	jetBlue

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

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 Francisco to London in May from $680

Return flights