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

Return flights

22 Sep - 03 Oct	China Southern
15 Sep - 15 Oct	China Southern
12 Sep - 12 Oct	China Southern
08 Sep - 15 Sep	China Southern
15 Sep - 29 Sep	China Southern
01 Sep - 12 Sep	China Southern
25 Sep - 16 Oct	China Southern
08 Sep - 29 Sep	China Southern
20 Sep - 02 Oct	China Southern
20 Sep - 27 Sep	Air China
01 Sep - 14 Sep	China Southern
01 Sep - 30 Sep	Wizz Air UK
06 Sep - 29 Sep	Wizz Air UK
22 Sep - 28 Sep	China Southern
23 Sep - 05 Oct	Wizz Air UK
08 Sep - 11 Sep	China Eastern
21 Sep - 02 Oct	Wizz Air UK
26 Sep - 16 Oct	China Southern
28 Sep - 11 Oct	China Eastern
21 Sep - 03 Oct	Wizz Air UK

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 526€

Return flights