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

Return flights

05 May - 12 May	Finnair
04 May - 12 May	Iberia
06 May - 13 May	British Airways
13 May - 20 May	Aer Lingus
11 May - 18 May	Iberia
02 May - 10 May	Delta
15 May - 20 May	Icelandair
06 May - 16 May	Iberia
01 May - 10 May	Finnair
10 May - 26 May	Air Canada
17 May - 09 Jun	Lufthansa
31 May - 10 Jun	Iberia
28 May - 17 Jun	Finnair
25 May - 07 Jun	Aer Lingus
26 May - 23 Jun	SWISS
26 May - 05 Jun	SWISS
28 May - 08 Jun	Finnair
31 May - 26 Jun	Finnair
24 May - 08 Jun	SWISS
23 May - 07 Jun	Aer Lingus

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.

Book a cheap hotel in Lisbon

Cheap car rent in Lisbon

Cheapest return flights from Chicago to Lisbon in May from 403€

Return flights