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

Return flights

30 Dec - 26 Jan	Air Canada
29 Dec - 16 Jan	Air Canada
30 Dec - 18 Jan	Lufthansa	direct
27 Dec - 27 Jan	Air Canada
27 Dec - 20 Jan	Air Canada
27 Dec - 27 Jan	Lufthansa	direct
27 Dec - 20 Jan	Lufthansa	direct
28 Dec - 16 Jan	Air Canada
28 Dec - 15 Jan	Air Canada
25 Dec - 20 Jan	Air Canada
23 Dec - 31 Dec	Delta
23 Dec - 28 Dec	Air France
24 Dec - 29 Dec	Air France
24 Dec - 28 Dec	Air France
23 Dec - 30 Dec	Delta
25 Dec - 31 Dec	Delta
26 Dec - 31 Dec	Delta
25 Dec - 29 Dec	Air France
25 Dec - 29 Dec	British Airways	direct
26 Dec - 29 Dec	Air Canada	direct

Also check the deals for one-way flights from Montreal 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 Montreal to London in December from $683

Return flights