AirHint found the following cheapest return flights from Montreal (YUL) to Sydney (SYD) in October 2025 (see full year).

Return flights

15 Oct - 22 Oct	WestJet
17 Oct - 24 Oct	Porter Airlines (Canada) Ltd
01 Oct - 22 Oct	Air Canada
23 Oct - 30 Oct	WestJet
29 Oct - 05 Nov	WestJet
21 Oct - 28 Oct	WestJet
27 Oct - 03 Nov	WestJet
28 Oct - 04 Nov	WestJet
16 Oct - 23 Oct	WestJet
18 Oct - 25 Oct	WestJet
22 Oct - 29 Oct	Porter Airlines (Canada) Ltd
30 Oct - 06 Nov	Porter Airlines (Canada) Ltd
25 Oct - 01 Nov	Porter Airlines (Canada) Ltd
20 Oct - 27 Oct	Porter Airlines (Canada) Ltd
26 Oct - 02 Nov	WestJet
14 Oct - 21 Oct	WestJet
14 Oct - 01 Nov	Porter Airlines (Canada) Ltd
31 Oct - 07 Nov	Porter Airlines (Canada) Ltd
01 Oct - 12 Nov	United

Also check the deals for one-way flights from Montreal to Sydney 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.

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Cheapest return flights from Montreal to Sydney in October from 904€

Return flights