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Cheap flights from London to Siem Reap from £278

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 28/2. 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
0 bags

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Cheap return flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
11:05 - 18:05
LGW
-
SAI
24h 00m
2 stops
Multiple Airlines Logo
19:05 - 07:00
SAI
-
LGW
41h 55m
2 stops
£521Multiple Airlines
Mon, 9 Mar - Tue, 31 Mar
Multiple Airlines Logo
12:35 - 18:05
LGW
-
SAI
23h 30m
2 stops
Multiple Airlines Logo
19:05 - 06:35
SAI
-
LGW
41h 30m
2 stops
£556Multiple Airlines
Mon, 18 May - Sun, 24 May
Multiple Airlines Logo
06:00 - 18:45
LHR
-
SAI
30h 45m
2 stops
Multiple Airlines Logo
10:30 - 17:50
SAI
-
LHR
37h 20m
2 stops
£560Multiple Airlines
Thu, 18 Jun - Thu, 25 Jun
Lufthansa Logo
17:50 - 18:45
LHR
-
SAI
18h 55m
2 stops
Lufthansa Logo
16:00 - 08:40
SAI
-
LHR
22h 40m
2 stops
£573Lufthansa
Mon, 18 May - Sun, 24 May
Multiple Airlines Logo
06:00 - 18:45
LHR
-
SAI
30h 45m
2 stops
Multiple Airlines Logo
10:30 - 07:55
SAI
-
LHR
27h 25m
2 stops
£579Multiple Airlines
Thu, 18 Jun - Thu, 25 Jun
SWISS Logo
18:40 - 09:40
LHR
-
SAI
33h 00m
2 stops
SWISS Logo
10:30 - 11:20
SAI
-
LHR
30h 50m
2 stops
£588SWISS
Thu, 18 Jun - Thu, 25 Jun
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
27h 30m
3 stops
China Eastern Logo
22:00 - 14:00
SAI
-
LGW
47h 00m
2 stops
£600China Eastern
Mon, 2 Mar - Tue, 10 Mar
China Eastern Logo
21:00 - 21:00
LHR
-
SAI
65h 00m
3 stops
China Eastern Logo
22:00 - 17:30
SAI
-
LHR
26h 30m
2 stops
£614China Eastern
Mon, 2 Mar - Tue, 10 Mar
Malaysia Airlines Logo
21:25 - 10:00
LHR
-
SAI
29h 35m
1 stop
Malaysia Airlines Logo
11:00 - 15:25
SAI
-
LHR
35h 25m
1 stop
£620Malaysia Airlines
Tue, 24 Feb - Tue, 3 Mar
SWISS Logo
09:15 - 18:45
LCY
-
SAI
27h 30m
2 stops
SWISS Logo
16:00 - 09:10
SAI
-
LCY
23h 10m
2 stops
£656SWISS
Mon, 18 May - Sun, 24 May

Emirates flights from London to Siem Reap

Our best Emirates deals on London to Siem Reap flight tickets
Emirates
8 Mar
LGW20:25London Gatwick
41h 45m
2 stops
SAI21:10Siem Reap–Angkor Intl
31 Mar
SAI23:50Siem Reap–Angkor Intl
37h 30m
2 stops
LGW07:20London Gatwick
£726
Emirates
3 Mar
LGW20:25London Gatwick
41h 45m
2 stops
SAI21:10Siem Reap–Angkor Intl
31 Mar
SAI23:50Siem Reap–Angkor Intl
37h 30m
2 stops
LGW07:20London Gatwick
£731
Emirates
3 Mar
LGW20:25London Gatwick
41h 45m
2 stops
SAI21:10Siem Reap–Angkor Intl
31 Mar
SAI23:50Siem Reap–Angkor Intl
37h 30m
2 stops
LGW07:20London Gatwick
£732

KLM flights from London to Siem Reap

Our best KLM deals on London to Siem Reap flight tickets
KLM
1 Apr
LCY09:20London City
20h 55m
2 stops
SAI12:15Siem Reap–Angkor Intl
18 Apr
SAI19:25Siem Reap–Angkor Intl
30h 50m
2 stops
LCY20:15London City
£1,682
KLM
1 Apr
LCY09:20London City
20h 55m
2 stops
SAI12:15Siem Reap–Angkor Intl
18 Apr
SAI19:25Siem Reap–Angkor Intl
30h 50m
2 stops
LCY20:15London City
£1,683
KLM
1 Apr
LCY09:20London City
20h 55m
2 stops
SAI12:15Siem Reap–Angkor Intl
18 Apr
SAI19:25Siem Reap–Angkor Intl
30h 50m
2 stops
LCY20:15London City
£1,695

momondo Fare Finder

 
Customise your flight search to find flights from London to 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 7 February 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

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

Mon 9/3

11:05-18:05

2 stops24h 00m

Siem Reap–Angkor Intl

Tue 31/3

19:05-07:00

2 stops41h 55m

£521

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

Mon 18/5

12:35-18:05

2 stops23h 30m

Siem Reap–Angkor Intl

Sun 24/5

19:05-06:35

2 stops41h 30m

£556

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Thu 18/6

06:00-18:45

2 stops30h 45m

Siem Reap–Angkor Intl

Thu 25/6

10:30-17:50

2 stops37h 20m

£560

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Mon 18/5

17:50-18:45

2 stops18h 55m

Siem Reap–Angkor Intl

Sun 24/5

16:00-08:40

2 stops22h 40m

£573

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Thu 18/6

06:00-18:45

2 stops30h 45m

Siem Reap–Angkor Intl

Thu 25/6

10:30-07:55

2 stops27h 25m

£579

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Thu 18/6

18:40-09:40

2 stops33h 00m

Siem Reap–Angkor Intl

Thu 25/6

10:30-11:20

2 stops30h 50m

£588

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

Mon 2/3

10:30-21:00

3 stops27h 30m

Siem Reap–Angkor Intl

Tue 10/3

22:00-14:00

2 stops47h 00m

£600

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Mon 2/3

21:00-21:00

3 stops65h 00m

Siem Reap–Angkor Intl

Tue 10/3

22:00-17:30

2 stops26h 30m

£614

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

Tue 24/2

21:25-10:00

1 stop29h 35m

Siem Reap–Angkor Intl

Tue 3/3

11:00-15:25

1 stop35h 25m

£620

LondonSiem Reap

LCY - SAI

LCYSAI

London City

Mon 18/5

09:15-18:45

2 stops27h 30m

Siem Reap–Angkor Intl

Sun 24/5

16:00-09:10

2 stops23h 10m

£656

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 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 typical price of a round-trip flight between London and Siem Reap?

What is the cheapest month to fly to Siem Reap?

The month of September is, on average, the cheapest month to fly to Siem Reap from London, with most prices found around £678. If you don’t want to visit Siem Reap in September, then you should wait until April to fly from London, when ticket prices are also cheap, with an average price of £731.

How far in advance should I book a flight to Siem Reap?

You are more likely to see cheaper flights to Siem Reap from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Siem Reap for around £786 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Siem Reap from London for as low as £666 on momondo.

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

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

How have London to Siem Reap flight prices changed over time?

As of February 2026, prices for London to Siem Reap flights are approximately 1% cheaper when compared to flights at the same time last year.

When to book flights from London to Siem Reap

Are you open to changing your travel dates? Check out the ideal times to fly from London to Siem Reap according to our flight data. Find out which month and days have the cheapest flights.
Estimated return price

Cheap London to Siem Reap (LON to SAI) flight deals and tips

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

Fastest flight time

15h 20m

Direct flights

None
The fastest flight from London to Siem Reap takes 15h 20m
There are no direct flights from London to Siem Reap. There are no popular flight routes from London to Siem Reap.
Search flight deals

  • How far is London to Siem Reap–Angkor Intl by plane?

    The straight-line distance from London to Siem Reap–Angkor Intl is 6077.6 mi. By plane, this route typically takes 15h 20m.

  • When did momondo last update prices for flights from London to Siem Reap–Angkor Intl Airport?

    Prices for flights from London to Siem Reap–Angkor Intl Airport are updated daily.

  • How many operators does momondo search for flights from London to Siem Reap–Angkor Intl Airport?

  • How old do you have to be to fly from London to Siem Reap–Angkor Intl Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from London to Siem Reap–Angkor Intl Airport.

  • What documentation or ID do you need to fly to Siem Reap–Angkor Intl Airport?

    The travel and health documents you'll need for your trip to Siem Reap–Angkor Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Siem Reap–Angkor Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from London to Siem Reap?

Best airlines flying from London to Siem Reap

Compare and see reviews for airlines that fly from London to Siem Reap with momondo
Airline
Rating
Free Cancellation
Price
Austrian AirlinesPriceFrom £533Free CancellationRating
7.5
896 reviews
Search Austrian Airlines flights
LufthansaPriceFrom £591Free CancellationRating
6.8
7,772 reviews
Search Lufthansa flights
Vietnam AirlinesPriceFrom £610Free CancellationRating
7.6
224 reviews
Search Vietnam Airlines flights
Singapore AirlinesPriceFrom £657Free CancellationRating
8.2
1,451 reviews
Search Singapore Airlines flights
Thai AirwaysPriceFrom £849Free CancellationRating
7.8
382 reviews
Search Thai Airways flights

Why use momondo?

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

Finding the right flight to Siem Reap from London is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Siem Reap quick and easy, saving you time and money.

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

Yes. All flights to Siem Reap from London on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from London to Siem Reap.

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

Yes. momondo can track prices for London to Siem Reap flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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Airlines are sorted and displayed according to clicks in the past 7 days on momondo
Singapore Airlines
Vietnam Airlines
Thai Airways
Lufthansa
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