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

Return flights

17 Oct - 24 Oct	Frontier Airlines
17 Oct - 27 Oct	Frontier Airlines
14 Oct - 18 Oct	jetBlue
22 Oct - 29 Oct	Alaska Airlines
14 Oct - 21 Oct	Alaska Airlines
04 Oct - 11 Oct	British Airways
17 Oct - 25 Oct	Iberia
01 Oct - 25 Oct	Iberia
21 Oct - 01 Nov	Alaska Airlines
22 Oct - 01 Nov	Alaska Airlines
20 Oct - 27 Oct	Alaska Airlines
21 Oct - 28 Oct	Alaska Airlines

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

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.

Book a cheap hotel in London

Cheap car rent in London

Cheapest return flights from Ontario to London in October from $672

Return flights