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

Return flights

02 May - 10 May	Icelandair
06 May - 13 May	Iberia
05 May - 12 May	Iberia
01 May - 16 May	Scandinavian Airlines
09 May - 16 May	TAP	direct
18 May - 25 May	SWISS
12 May - 17 May	Finnair
15 May - 23 May	Iberia
17 May - 06 Jun	Iberia
20 May - 31 May	Lufthansa
15 May - 06 Jun	Lufthansa
21 May - 31 May	Lufthansa
21 May - 13 Jun	Air Canada
25 May - 01 Jun	Air Canada
30 May - 06 Jun	Air Canada
17 May - 06 Jun	TAP	direct
15 May - 06 Jun	TAP	direct
30 May - 06 Jun	TAP	direct

Also check the deals for one-way flights from Chicago 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 Chicago to Lisbon in May from $480

Return flights