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

Return flights

07 Dec - 14 Dec	Air France
08 Dec - 24 Dec	Lufthansa
14 Dec - 24 Dec	Air France
10 Dec - 16 Dec	Delta
07 Dec - 18 Dec	Delta
09 Dec - 16 Dec	Delta
03 Dec - 11 Dec	Lufthansa
03 Dec - 10 Dec	Austrian Airlines
02 Dec - 09 Dec	Lufthansa
30 Dec - 13 Jan	United	direct
05 Dec - 12 Dec	British Airways
15 Dec - 06 Jan	Lufthansa
12 Dec - 11 Jan	KLM
28 Dec - 10 Jan	United
16 Dec - 07 Jan	Virgin Atlantic
27 Dec - 07 Jan	Austrian Airlines
25 Dec - 08 Jan	United
15 Dec - 07 Jan	United
29 Dec - 09 Jan	United
19 Dec - 13 Jan	Frontier Airlines

Also check the deals for one-way flights from Denver to London 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 London in December from 469€

Return flights