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

Return flights

08 Apr - 21 Apr	KLM
01 Apr - 08 Apr	British Airways
01 Apr - 07 Apr	British Airways
30 Apr - 05 May	Lufthansa
15 Apr - 28 Apr	KLM
19 Apr - 28 Apr	KLM
08 Apr - 23 Apr	KLM
01 Apr - 06 Apr	British Airways
20 Apr - 26 Apr	Virgin Atlantic
19 Apr - 02 May	Virgin Atlantic
01 Apr - 13 Apr	British Airways
08 Apr - 12 Apr	British Airways
30 Apr - 07 May	British Airways
24 Apr - 04 May	British Airways
30 Apr - 10 May	British Airways
30 Apr - 04 May	British Airways
11 Apr - 11 May	KLM
18 Apr - 27 May	Iberia
22 Apr - 06 May	British Airways
21 Apr - 27 May	British Airways

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

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 April from 562€

Return flights