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

Return flights

09 May - 23 May	Air Canada
02 May - 23 May	Air Canada
02 May - 10 May	Air Canada
19 May - 02 Jun	Iberia
05 May - 30 May	Iberia
20 May - 24 May	Lufthansa
18 May - 13 Jun	Lufthansa
21 May - 28 May	United
16 May - 06 Jun	Iberia
05 May - 30 May	TAP	direct
12 May - 01 Jun	Air Canada
27 May - 11 Jun	Air Canada
21 May - 13 Jun	Air Canada
01 May - 08 May	TAP	direct
27 May - 20 Jun	Air Canada
02 May - 23 May	TAP	direct
21 May - 28 May	TAP	direct
21 May - 13 Jun	TAP	direct
16 May - 06 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.

Book a cheap hotel in Lisbon

Cheap car rent in Lisbon

Cheapest return flights from San Francisco to Lisbon in May from $581

Return flights