AirHint found the following cheapest return flights from Sydney (SYD) to Phnom-penh (PNH) in September 2025 (see full year).

Return flights

18 Sep - 21 Sep	China Southern
10 Sep - 16 Sep	China Southern
06 Sep - 22 Sep	AirAsia X
06 Sep - 23 Sep	AirAsia X
11 Sep - 23 Sep	AirAsia X
03 Sep - 23 Sep	AirAsia X
06 Sep - 18 Sep	AirAsia X
13 Sep - 20 Sep	AirAsia X
14 Sep - 21 Sep	AirAsia X
11 Sep - 18 Sep	AirAsia X
30 Sep - 21 Oct	AirAsia X
19 Sep - 06 Oct	AirAsia X
16 Sep - 06 Oct	AirAsia X
30 Sep - 06 Oct	AirAsia X
19 Sep - 03 Oct	AirAsia X
16 Sep - 03 Oct	AirAsia X
14 Sep - 03 Oct	AirAsia X
30 Sep - 03 Oct	AirAsia X
13 Sep - 03 Oct	AirAsia X
30 Sep - 14 Oct	AirAsia X

Also check the deals for one-way flights from Sydney to Phnom-penh 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 Phnom-penh in September from $491

Return flights