AirHint found the following cheapest return flights from Denver (DEN) to Madrid (MAD) in December 2025 (see full year).

Return flights

31 Dec - 13 Jan	Lufthansa
31 Dec - 21 Jan	Lufthansa
31 Dec - 16 Jan	Lufthansa
02 Dec - 09 Dec	Lufthansa
10 Dec - 23 Dec	Lufthansa
03 Dec - 10 Dec	Lufthansa
01 Dec - 08 Dec	Air Canada
08 Dec - 15 Dec	Air Canada
09 Dec - 23 Dec	Air Canada
09 Dec - 16 Dec	Air Canada
10 Dec - 17 Dec	Air Canada
31 Dec - 24 Jan	Brussels Airlines
04 Dec - 11 Dec	Brussels Airlines
07 Dec - 14 Dec	Iberia
28 Dec - 17 Jan	British Airways
31 Dec - 11 Jan	Air Canada
24 Dec - 17 Jan	Lufthansa
31 Dec - 07 Jan	Brussels Airlines
15 Dec - 06 Jan	Frontier Airlines
30 Dec - 06 Jan	Frontier Airlines

Also check the deals for one-way flights from Denver to Madrid 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 Denver to Madrid in December from $441

Return flights