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

Return flights

15 Sep - 15 Oct	Air China
15 Sep - 10 Oct	Air China
29 Sep - 05 Oct	Air China
22 Sep - 03 Oct	China Southern
29 Sep - 06 Oct	China Southern
27 Sep - 10 Oct	Air China
29 Sep - 14 Oct	Air China
15 Sep - 05 Oct	China Southern
12 Sep - 12 Oct	China Southern
27 Sep - 11 Oct	Air China
05 Sep - 14 Sep	Air China
04 Sep - 15 Sep	China Southern
01 Sep - 15 Sep	China Southern
14 Sep - 28 Sep	SWISS
22 Sep - 28 Sep	SWISS
16 Sep - 23 Sep	SWISS
15 Sep - 29 Sep	Wizz Air UK
01 Sep - 30 Sep	Wizz Air UK
08 Sep - 18 Sep	China Southern
11 Sep - 18 Sep	China Southern

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 396€

Return flights