Cheapest return flights from Ontario to London in September from $525

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

Return flights

09 Sep - 19 Sep Delta
01 Sep - 16 Sep Iberia
03 Sep - 10 Sep Iberia
14 Sep - 24 Sep Iberia
01 Sep - 11 Sep Iberia
01 Sep - 10 Sep Iberia
01 Sep - 12 Sep Iberia
01 Sep - 21 Sep Iberia
01 Sep - 08 Sep Iberia
04 Sep - 16 Sep Iberia
14 Sep - 05 Oct Iberia
26 Sep - 05 Oct Iberia
23 Sep - 09 Oct Iberia
25 Sep - 19 Oct British Airways
15 Sep - 01 Oct China Airlines

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

Skyscanner

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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