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

Return flights

02 Sep - 09 Sep	Iberia
03 Sep - 10 Sep	Iberia
09 Sep - 16 Sep	Iberia
10 Sep - 17 Sep	Iberia
05 Sep - 12 Sep	Iberia
11 Sep - 18 Sep	Iberia
04 Sep - 18 Sep	Iberia
04 Sep - 11 Sep	Iberia
01 Sep - 20 Sep	Iberia
01 Sep - 08 Sep	Iberia
28 Sep - 10 Oct	Iberia
30 Sep - 07 Oct	Iberia
29 Sep - 06 Oct	Iberia
26 Sep - 03 Oct	Iberia
28 Sep - 05 Oct	Iberia
27 Sep - 04 Oct	Iberia
24 Sep - 01 Oct	Iberia
25 Sep - 02 Oct	Iberia

Also check the deals for one-way flights from Ontario to Dublin 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 Ontario to Dublin in September from 476€

Return flights