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

Return flights

30 Sep - 08 Oct	Ryanair
17 Sep - 01 Oct	Ryanair
24 Sep - 29 Sep	Ryanair
22 Sep - 13 Oct	Ryanair
22 Sep - 03 Oct	Ryanair
24 Sep - 01 Oct	Ryanair
29 Sep - 10 Oct	Ryanair
04 Sep - 17 Sep	Ryanair
05 Sep - 06 Oct	AJet
16 Sep - 25 Sep	Ryanair
30 Sep - 10 Oct	Ryanair
05 Sep - 21 Sep	Pegasus Airlines
03 Sep - 10 Sep	Pegasus Airlines
21 Sep - 06 Oct	Emirates
23 Sep - 30 Sep	Emirates
26 Sep - 06 Oct	Emirates
15 Sep - 26 Sep	Emirates
06 Sep - 13 Sep	AJet
13 Sep - 20 Sep	Emirates
21 Sep - 26 Sep	Emirates

Also check the deals for one-way flights from London 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 London to Phnom-penh in September from 695€

Return flights