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

Return flights

05 Dec - 08 Dec	Aer Lingus
05 Dec - 18 Jan	WestJet
02 Dec - 06 Dec	Air Canada
29 Dec - 24 Jan	Air Canada
23 Dec - 17 Jan	Air Canada
22 Dec - 17 Jan	Air Canada
13 Dec - 27 Dec	Air Canada
15 Dec - 09 Jan	WestJet
16 Dec - 10 Jan	Porter Airlines (Canada) Ltd
21 Dec - 10 Jan	Air Canada
20 Dec - 10 Jan	Porter Airlines (Canada) Ltd
18 Dec - 10 Jan	Porter Airlines (Canada) Ltd
25 Dec - 02 Jan	WestJet
21 Dec - 30 Dec	Air Canada
23 Dec - 30 Dec	Virgin Atlantic

Also check the deals for one-way flights from Ottawa 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 Ottawa to London in December from $674

Return flights