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

Return flights

05 May - 19 May	United
04 May - 18 May	Air France
13 May - 21 May	Lufthansa
05 May - 19 May	TAP	direct
09 May - 16 May	KLM
18 May - 23 May	KLM
16 May - 24 May	Virgin Atlantic
08 May - 15 May	TAP	direct
26 May - 09 Jun	United
25 May - 01 Jun	SWISS
24 May - 31 May	WestJet
23 May - 30 May	WestJet
23 May - 14 Jun	United
28 May - 04 Jun	TAP	direct

Also check the deals for one-way flights from San Francisco to Lisbon 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 Lisbon in May from 474€

Return flights