Cheap flights from London to Siem Reap from £335

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from London to Siem Reap departing on 9/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Find the cheapest flights from London to Siem Reap

Cheap return flights

Enter your travel dates to find the best prices.
SWISS Logo
20:05 - 18:55
LHR
-
SAI
40h 50m
2 stops
SWISS Logo
09:40 - 21:45
SAI
-
LHR
18h 05m
2 stops
£596SWISS
Tue, 1 Sep - Tue, 22 Sep
SWISS Logo
09:05 - 18:55
LGW
-
SAI
27h 50m
2 stops
SWISS Logo
09:40 - 17:50
SAI
-
LGW
38h 10m
2 stops
£596SWISS
Sun, 30 Aug - Tue, 22 Sep
SWISS Logo
18:40 - 09:50
LHR
-
SAI
32h 10m
2 stops
SWISS Logo
09:55 - 08:05
SAI
-
LHR
29h 10m
2 stops
£605SWISS
Sat, 7 Nov - Mon, 23 Nov
Multiple Airlines Logo
13:35 - 18:55
LHR
-
SAI
23h 20m
2 stops
Multiple Airlines Logo
09:40 - 21:45
SAI
-
LHR
18h 05m
2 stops
£615Multiple Airlines
Wed, 2 Sep - Wed, 23 Sep
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
51h 30m
2 stops
China Eastern Logo
22:00 - 14:00
SAI
-
LGW
47h 00m
2 stops
£627China Eastern
Thu, 12 Nov - Thu, 19 Nov
Lufthansa Logo
17:50 - 18:55
LHR
-
SAI
19h 05m
2 stops
Lufthansa Logo
19:35 - 17:05
SAI
-
LHR
27h 30m
2 stops
£629Lufthansa
Sat, 3 Oct - Sun, 18 Oct
Multiple Airlines Logo
20:25 - 18:55
LHR
-
SAI
40h 30m
2 stops
Multiple Airlines Logo
09:40 - 21:45
SAI
-
LHR
18h 05m
2 stops
£638Multiple Airlines
Wed, 19 Aug - Wed, 16 Sep
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
51h 30m
2 stops
China Eastern Logo
22:00 - 06:30
SAI
-
LGW
39h 30m
2 stops
£676China Eastern
Thu, 12 Nov - Thu, 19 Nov
Emirates Logo
21:05 - 21:30
STN
-
SAI
18h 25m
2 stops
Emirates Logo
12:55 - 12:55
SAI
-
STN
30h 00m
2 stops
£782Emirates
Mon, 31 Aug - Sun, 13 Sep
Emirates Logo
14:55 - 21:30
STN
-
SAI
24h 35m
2 stops
Emirates Logo
12:55 - 12:55
SAI
-
STN
30h 00m
2 stops
£793Emirates
Wed, 2 Sep - Wed, 30 Sep

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Emirates flights from London to Region of Siem Reap

Our best Emirates deals on London to Region of Siem Reap flight tickets
Emirates
9 Nov
LHR15:50London Heathrow
22h 20m
2 stops
SAI21:10Siem Reap–Angkor Intl
24 Nov
SAI23:50Siem Reap–Angkor Intl
27h 10m
2 stops
LHR20:00London Heathrow
£764
Emirates
2 Sept
LGW14:35London Gatwick
24h 55m
2 stops
SAI21:30Siem Reap–Angkor Intl
30 Sept
SAI12:55Siem Reap–Angkor Intl
29h 40m
2 stops
LGW12:35London Gatwick
£772
Emirates
31 Aug
STN21:05London Stansted
18h 25m
2 stops
SAI21:30Siem Reap–Angkor Intl
13 Sept
SAI12:55Siem Reap–Angkor Intl
30h 00m
2 stops
STN12:55London Stansted
£782

Singapore Airlines flights from London to Region of Siem Reap

Our best Singapore Airlines deals on London to Region of Siem Reap flight tickets
Singapore Airlines
8 Nov
LHR20:35London Heathrow
36h 20m
1 stop
SAI15:55Siem Reap–Angkor Intl
24 Nov
SAI10:45Siem Reap–Angkor Intl
35h 35m
1 stop
LHR15:20London Heathrow
£821
Singapore Airlines
12 Nov
LGW09:20London Gatwick
17h 30m
1 stop
SAI09:50Siem Reap–Angkor Intl
19 Nov
SAI10:45Siem Reap–Angkor Intl
29h 15m
1 stop
LGW09:00London Gatwick
£831
Singapore Airlines
12 Nov
LGW13:00London Gatwick
19h 55m
1 stop
SAI15:55Siem Reap–Angkor Intl
19 Nov
SAI10:45Siem Reap–Angkor Intl
29h 15m
1 stop
LGW09:00London Gatwick
£831

momondo Fare Finder

 
Customise your flight search to find flights from London to Region of Siem Reap that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 279,928 searches. Data last updated 27 June 2026.
Use the filters below to find and compare flights from London to Siem Reap that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Tue 1/9

20:05-18:55

2 stops40h 50m

Siem Reap–Angkor Intl

Tue 22/9

09:40-21:45

2 stops18h 05m

£596

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

Sun 30/8

09:05-18:55

2 stops27h 50m

Siem Reap–Angkor Intl

Tue 22/9

09:40-17:50

2 stops38h 10m

£596

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Sat 7/11

18:40-09:50

2 stops32h 10m

Siem Reap–Angkor Intl

Mon 23/11

09:55-08:05

2 stops29h 10m

£605
Fastest return journey

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Wed 2/9

13:35-18:55

2 stops23h 20m

Siem Reap–Angkor Intl

Wed 23/9

09:40-21:45

2 stops18h 05m

£615

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

Thu 12/11

10:30-21:00

2 stops51h 30m

Siem Reap–Angkor Intl

Thu 19/11

22:00-14:00

2 stops47h 00m

£627

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Sat 3/10

17:50-18:55

2 stops19h 05m

Siem Reap–Angkor Intl

Sun 18/10

19:35-17:05

2 stops27h 30m

£629

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Wed 19/8

20:25-18:55

2 stops40h 30m

Siem Reap–Angkor Intl

Wed 16/9

09:40-21:45

2 stops18h 05m

£638

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

Thu 12/11

10:30-21:00

2 stops51h 30m

Siem Reap–Angkor Intl

Thu 19/11

22:00-06:30

2 stops39h 30m

£676

LondonSiem Reap

STN - SAI

STNSAI

London Stansted

Mon 31/8

21:05-21:30

2 stops18h 25m

Siem Reap–Angkor Intl

Sun 13/9

12:55-12:55

2 stops30h 00m

£782

LondonSiem Reap

STN - SAI

STNSAI

London Stansted

Wed 2/9

14:55-21:30

2 stops24h 35m

Siem Reap–Angkor Intl

Wed 30/9

12:55-12:55

2 stops30h 00m

£793

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Siem Reap from

How to get the cheapest flight ticket from London to Region of Siem Reap

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Region of Siem Reap?

If you’re not able to fly to Region of Siem Reap in December, then November is your next best option. Flight prices from London to Region of Siem Reap during November average around £190.

Can stopping save me money on London to Region of Siem Reap flights?

You could potentially save up to 22% on your flight if you consider stops on a London to Region of Siem Reap flight.

Cheap London to Region of Siem Reap flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from London to Region of Siem Reap

Fastest flight time

18h 25m

Direct flights

None
The fastest flight from London to Region of Siem Reap takes 18h 25m
There are no direct flights from London to Region of Siem Reap. There are no popular flight routes from London to Region of Siem Reap.

Frequently asked questions about flying from London to Siem Reap

  • When did momondo last update prices for flights from London to Siem Reap?

    Prices for flights from London to Siem Reap are updated daily.

  • How many operators does momondo search for flights from London to Siem Reap?

  • How old do you have to be to fly from London to Siem Reap?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from London to Siem Reap.

  • What documentation or ID do you need to fly to Siem Reap?

    The required travel and health documents for your Siem Reap trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Siem Reap. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

Best airlines flying from London to Region of Siem Reap

Compare and see reviews for airlines that fly from London to Region of Siem Reap with momondo
Airline
Rating
Free Cancellation
Price
Austrian AirlinesPriceFrom £549Free CancellationRating
7.6
939 reviews
Search Austrian Airlines flights
Vietnam AirlinesPriceFrom £627Free CancellationRating
7.7
273 reviews
Search Vietnam Airlines flights
Singapore AirlinesPriceFrom £676Free CancellationRating
8.2
1,555 reviews
Search Singapore Airlines flights
Thai AirwaysPriceFrom £837Free CancellationRating
7.9
407 reviews
Search Thai Airways flights

Why use momondo?

Why should I use momondo to find a flight deal from London to Siem Reap?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from London to Siem Reap. momondo saves you time and could save you money on your trip.

Can I find flights from London to Siem Reap with flexible booking policies on momondo?

Flights from London to Siem Reap with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from London to Siem Reap?

momondo provides multiple filters to help you find the best flight to Siem Reap from London. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from London to Siem Reap right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of London to Siem Reap flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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1 adult
Mon 27/7
Mon 3/8

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