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

Return flights

10 Oct - 15 Oct	Frontier Airlines
10 Oct - 14 Oct	Frontier Airlines
20 Oct - 15 Nov	Frontier Airlines
09 Oct - 15 Oct	Frontier Airlines
14 Oct - 08 Nov	Iberia
16 Oct - 08 Nov	Iberia
12 Oct - 19 Oct	Iberia
12 Oct - 01 Nov	Iberia

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 614€

Return flights