Cheapest return flights from Ontario to London in September from $722

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

Return flights

20 Sep - 01 Oct Frontier Airlines
19 Sep - 11 Oct Frontier Airlines
24 Sep - 14 Oct Alaska Airlines
01 Sep - 30 Sep Frontier Airlines
15 Sep - 11 Oct British Airways
24 Sep - 01 Oct Alaska Airlines
21 Sep - 01 Oct Alaska Airlines
04 Sep - 11 Sep KLM
17 Sep - 11 Oct British Airways
12 Sep - 26 Sep Iberia
01 Sep - 08 Sep Iberia

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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