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

Return flights

06 May - 13 May	British Airways
07 May - 14 May	Air Canada
08 May - 15 May	Finnair
19 May - 02 Jun	SWISS
08 May - 15 May	TAP	direct
21 May - 28 May	United
21 May - 25 May	Scandinavian Airlines
06 May - 13 May	TAP	direct
22 May - 29 May	Finnair
22 May - 05 Jun	Finnair
22 May - 30 May	TAP	direct
22 May - 06 Jun	TAP	direct
22 May - 29 May	TAP	direct
22 May - 05 Jun	TAP	direct
22 May - 07 Jun	TAP	direct
22 May - 08 Jun	Finnair

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 478€

Return flights