AirHint found the following cheapest return flights from Sydney (SYD) to Kathmandu (KTM) in September 2025 (see full year).

Return flights

17 Sep - 24 Sep	AirAsia X
15 Sep - 20 Sep	VietJet Air
15 Sep - 21 Sep	VietJet Air
16 Sep - 22 Sep	VietJet Air
15 Sep - 15 Oct	VietJet Air
20 Sep - 21 Oct	Scoot
22 Sep - 21 Oct	VietJet Air
15 Sep - 14 Oct	VietJet Air
17 Sep - 30 Sep	VietJet Air
20 Sep - 20 Oct	Scoot
20 Sep - 27 Sep	China Eastern
23 Sep - 21 Oct	VietJet Air
24 Sep - 21 Oct	VietJet Air
21 Sep - 18 Oct	Scoot
14 Sep - 20 Sep	VietJet Air
21 Sep - 21 Oct	Scoot
30 Sep - 25 Oct	Hainan Airlines
18 Sep - 25 Sep	China Eastern
14 Sep - 16 Sep	Malaysia Airlines
16 Sep - 20 Sep	Malaysia Airlines

Also check the deals for one-way flights from Sydney to Kathmandu 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 Sydney to Kathmandu in September from 579€

Return flights