AirHint found the following cheapest return flights from Ontario (ONT) to London (LHR) in March 2026 (see full year).

Return flights

06 Mar - 19 Mar	KLM
12 Mar - 18 Mar	KLM
07 Mar - 17 Mar	KLM
04 Mar - 11 Mar	Delta
24 Mar - 02 Apr	Delta
31 Mar - 07 Apr	British Airways
31 Mar - 21 Apr	Iberia
03 Mar - 12 Mar	British Airways
01 Mar - 11 Mar	British Airways
02 Mar - 29 Apr	Virgin Atlantic
23 Mar - 31 Mar	Virgin Atlantic
25 Mar - 03 Apr	Iberia
08 Mar - 20 Mar	KLM
23 Mar - 30 Mar	Lufthansa
24 Mar - 03 Apr	Iberia
17 Mar - 02 Apr	Iberia
25 Mar - 06 Apr	Delta
23 Mar - 03 Apr	Air France
26 Mar - 07 Apr	Lufthansa
02 Mar - 09 Mar	British Airways

Also check the deals for one-way flights from Ontario to London in March.

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 Ontario to London in March from 530€

Return flights