AirHint found the following cheapest return flights from Chicago (ORD) to Lisbon (LIS) in December 2025 (see full year).

Return flights

02 Dec - 09 Dec	United
03 Dec - 10 Dec	TAP	direct
30 Dec - 15 Jan	British Airways
07 Dec - 14 Dec	Scandinavian Airlines
08 Dec - 15 Dec	United
07 Dec - 14 Dec	TAP	direct
12 Dec - 19 Dec	TAP	direct
09 Dec - 14 Dec	Scandinavian Airlines
02 Dec - 05 Dec	British Airways
13 Dec - 20 Dec	United
18 Dec - 25 Dec	United
21 Dec - 18 Jan	TAP	direct
27 Dec - 02 Jan	Scandinavian Airlines
22 Dec - 06 Jan	SWISS
23 Dec - 06 Jan	SWISS
18 Dec - 09 Jan	United
19 Dec - 09 Jan	TAP	direct
21 Dec - 06 Jan	SWISS
20 Dec - 18 Jan	Scandinavian Airlines
21 Dec - 10 Jan	SWISS

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

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 December from 417€

Return flights