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

Return flights

30 Dec - 06 Jan	KLM
31 Dec - 07 Jan	Air France
11 Dec - 18 Dec	British Airways
14 Dec - 21 Dec	British Airways
15 Dec - 22 Dec	British Airways
12 Dec - 19 Dec	British Airways
17 Dec - 24 Dec	British Airways
29 Dec - 05 Jan	United
15 Dec - 19 Dec	Scandinavian Airlines
30 Dec - 04 Jan	British Airways
28 Dec - 04 Jan	Air Canada
27 Dec - 03 Jan	Air Canada
26 Dec - 03 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 $721

Return flights