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

Return flights

05 Dec - 14 Dec	Air Canada
10 Dec - 24 Dec	Air Canada
03 Dec - 27 Dec	British Airways
07 Dec - 27 Dec	British Airways
12 Dec - 19 Dec	United
31 Dec - 07 Jan	Scandinavian Airlines
06 Dec - 27 Dec	British Airways
22 Dec - 12 Jan	jetBlue
13 Dec - 17 Jan	British Airways
12 Dec - 21 Dec	Air Canada
30 Dec - 06 Jan	Air Canada
06 Dec - 13 Dec	British Airways
13 Dec - 20 Dec	British Airways
25 Dec - 18 Jan	British Airways
26 Dec - 05 Jan	Iberia
23 Dec - 28 Dec	Scandinavian Airlines
31 Dec - 05 Jan	jetBlue
25 Dec - 01 Jan	Air Canada
25 Dec - 04 Jan	Scandinavian Airlines
20 Dec - 10 Jan	Air Canada

Also check the deals for one-way flights from Washington 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 Washington to Lisbon in December from $695

Return flights