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

Return flights

01 Dec - 07 Dec	Air China
01 Dec - 08 Dec	Air China
01 Dec - 22 Dec	Air China
29 Dec - 30 Jan	Etihad Airways
29 Dec - 31 Jan	Etihad Airways
06 Dec - 21 Dec	China Southern
07 Dec - 22 Dec	China Southern
09 Dec - 16 Dec	Vietnam Airlines
09 Dec - 13 Jan	Vietnam Airlines
27 Dec - 31 Jan	China Southern
09 Dec - 08 Jan	Vietnam Airlines
30 Dec - 13 Jan	Malaysia Airlines
24 Dec - 11 Jan	Singapore Airlines
27 Dec - 11 Jan	China Airlines
03 Dec - 15 Dec	Thai Airways
11 Dec - 08 Jan	British Airways
25 Dec - 20 Jan	British Airways
18 Dec - 28 Dec	China Southern
19 Dec - 30 Dec	Shenzhen Airlines
20 Dec - 27 Dec	Shenzhen Airlines

Also check the deals for one-way flights from London to Phnom-penh in December.

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 December from $597

Return flights