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
01 May - 10 May	Icelandair
19 May - 26 May	SWISS
20 May - 27 May	Air Canada
06 May - 13 May	TAP	direct
01 May - 10 May	TAP	direct
10 May - 31 May	TAP	direct
02 May - 10 May	TAP	direct
20 May - 27 May	TAP	direct
29 May - 14 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 $457

Return flights