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

Return flights

16 Aug - 21 Aug	Scandinavian Airlines
21 Aug - 28 Aug	Scandinavian Airlines
11 Aug - 18 Aug	KLM
24 Aug - 07 Sep	Turkish Airlines
17 Aug - 24 Aug	Air France
31 Aug - 07 Sep	Turkish Airlines
23 Aug - 06 Sep	Turkish Airlines
13 Aug - 20 Aug	KLM
05 Aug - 12 Aug	Air Canada
01 Aug - 26 Aug	Finnair
04 Aug - 11 Aug	Iberia
01 Aug - 29 Aug	Finnair
06 Aug - 13 Aug	Finnair
23 Aug - 06 Sep	TAP	direct

Also check the deals for one-way flights from Chicago to Lisbon in August.

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 August from $531

Return flights