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

Return flights

04 Dec - 11 Dec	Icelandair
02 Dec - 09 Dec	Icelandair
03 Dec - 08 Dec	Icelandair
01 Dec - 08 Dec	Icelandair
02 Dec - 08 Dec	Icelandair
01 Dec - 05 Dec	Icelandair
09 Dec - 09 Jan	Icelandair
08 Dec - 24 Dec	Virgin Atlantic
02 Dec - 09 Dec	British Airways	direct
08 Dec - 24 Dec	British Airways	direct
07 Dec - 24 Dec	British Airways	direct
30 Dec - 13 Jan	Delta
15 Dec - 10 Jan	Icelandair
16 Dec - 10 Jan	Icelandair
29 Dec - 24 Jan	Lufthansa
12 Dec - 11 Jan	Icelandair
24 Dec - 17 Jan	Icelandair
08 Dec - 07 Jan	Delta
22 Dec - 12 Jan	Air Canada
13 Dec - 12 Jan	United

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.

Book a cheap hotel in London

Cheap car rent in London

Cheapest return flights from Denver to London in December from 421€

Return flights