AirHint found the following cheapest return flights from Ontario (ONT) to London (LHR) in June 2025 (see full year).

Return flights

28 Jun - 19 Jul	jetBlue
25 Jun - 03 Jul	Iberia
25 Jun - 02 Jul	Iberia
25 Jun - 09 Jul	Iberia
24 Jun - 01 Jul	Iberia
24 Jun - 02 Jul	British Airways
21 Jun - 29 Jun	jetBlue
26 Jun - 03 Jul	Iberia
25 Jun - 30 Jun	Iberia
28 Jun - 12 Jul	jetBlue
26 Jun - 09 Jul	Iberia
24 Jun - 29 Jun	British Airways
19 Jun - 03 Jul	jetBlue
20 Jun - 27 Jun	jetBlue
23 Jun - 30 Jun	Frontier Airlines
19 Jun - 22 Jun	Delta
19 Jun - 24 Jun	Iberia
20 Jun - 25 Jun	Iberia
22 Jun - 28 Jun	Iberia
23 Jun - 27 Jun	Iberia

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

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 June from $1089

Return flights