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

Return flights

12 Sep - 16 Sep	Air India
13 Sep - 20 Sep	IndiGo
10 Sep - 14 Sep	Air India
14 Sep - 30 Sep	IndiGo
12 Sep - 17 Oct	Air India
13 Sep - 03 Oct	IndiGo
26 Sep - 10 Oct	Air India
10 Sep - 01 Oct	Air India
21 Sep - 05 Oct	Air India
14 Sep - 23 Sep	IndiGo
09 Sep - 07 Oct	Air India
11 Sep - 11 Oct	Air India
13 Sep - 01 Oct	Akasa Air
09 Sep - 23 Sep	Air India
10 Sep - 15 Sep	Air India
13 Sep - 30 Sep	IndiGo
12 Sep - 14 Sep	Air India
10 Sep - 18 Sep	Air India
23 Sep - 13 Oct	VietJet Air
15 Sep - 15 Oct	IndiGo

Also check the deals for one-way flights from Delhi to Sydney 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 Delhi to Sydney in September from $593

Return flights