AirHint found the following cheapest return flights from London (LON) to Toronto (YYZ) in September 2025 (see full year).

Return flights

18 Sep - 23 Sep	Air Canada
09 Sep - 23 Sep	SWISS
12 Sep - 20 Sep	Aer Lingus
02 Sep - 11 Sep	Aer Lingus
06 Sep - 14 Sep	Aer Lingus
06 Sep - 15 Sep	Aer Lingus
05 Sep - 12 Sep	Aer Lingus
13 Sep - 21 Sep	Aer Lingus
12 Sep - 15 Sep	Aer Lingus
18 Sep - 22 Sep	Aer Lingus
27 Sep - 06 Oct	Aer Lingus
24 Sep - 11 Oct	Aer Lingus
17 Sep - 08 Oct	Aer Lingus
25 Sep - 05 Oct	Aer Lingus
30 Sep - 15 Oct	Aer Lingus
09 Sep - 02 Oct	Aer Lingus
23 Sep - 09 Oct	Aer Lingus
22 Sep - 06 Oct	Aer Lingus
30 Sep - 07 Oct	Aer Lingus
25 Sep - 07 Oct	Aer Lingus

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

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 London to Toronto in September from $412

Return flights