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Cheap flights from London to Siem Reap, Cambodia from £239

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 24/1. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SAI
15 feb — 22 feb1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from London to Siem Reap

Discover tips and strategies to find the most affordable flight options for your journey from London (LON) to Siem Reap (SAI). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 16 gennaio 2026.

Round-trip from

£540

One-way from

£239

Popular in

December

Cheapest in

September

Average price

£732
18/2-23/3
  • 18/2-23/3
  • 4 total stops
  • 50h 30m total
  • London to Siem Reap
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24/1
  • 24/1
  • 2 total stops
  • 42h 30m total
  • London to Siem Reap
Search Deals
Highest demand for flights based on searches. 7% potential increase in price (£52 potential increase over avg. return price).
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Cheapest flight prices on average. 3% potential price decrease (£24 potential savings vs. average return price).
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Average for round-trip flights in January 2026
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Find flight deals from London to Siem Reap

Enter your travel dates to find the best prices.

Cheapest flights from London to Siem Reap
Explore the most affordable flight options available from London to Siem Reap. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 16 gennaio 2026.

mer 18/210:30
LGW
-
SAI
2 stops24h 35m
Multiple Airlines
lun 23/319:05
SAI
-
LGW
2 stops25h 55m
Multiple Airlines
Deal found 14/1£540
gio 14/516:25
LHR
-
SAI
2 stops20h 20m
Multiple Airlines
mar 2/609:40
SAI
-
LHR
2 stops18h 05m
Multiple Airlines
Deal found 14/1£545
mar 17/319:25
LHR
-
SAI
2 stops16h 20m
Multiple Airlines
mar 16/609:40
SAI
-
LHR
2 stops18h 05m
Multiple Airlines
Deal found 14/1£547
sab 21/1118:40
LHR
-
SAI
2 stops32h 10m
SWISS
mar 1/1209:55
SAI
-
LHR
2 stops18h 45m
SWISS
Deal found 14/1£548
ven 15/516:25
LHR
-
SAI
2 stops20h 20m
Lufthansa
lun 1/610:30
SAI
-
LHR
2 stops29h 25m
Lufthansa
Deal found 14/1£554
ven 15/513:40
LHR
-
SAI
2 stops23h 05m
Multiple Airlines
mar 2/609:40
SAI
-
LHR
2 stops28h 15m
Multiple Airlines
Deal found 14/1£559
mer 11/310:30
LGW
-
SAI
2 stops24h 35m
Multiple Airlines
ven 27/319:05
SAI
-
LGW
2 stops25h 55m
Multiple Airlines
Deal found 13/1£566
gio 14/519:15
LCY
-
SAI
2 stops32h 25m
SWISS
mar 2/610:30
SAI
-
LCY
2 stops28h 10m
SWISS
Deal found 14/1£579
ven 15/519:15
LCY
-
SAI
2 stops41h 30m
Multiple Airlines
mar 2/609:40
SAI
-
LCY
2 stops29h 00m
Multiple Airlines
Deal found 14/1£588
dom 1/1109:00
LHR
-
SAI
2 stops41h 50m
SWISS
dom 15/1109:55
SAI
-
LHR
2 stops18h 45m
SWISS
Deal found 14/1£594
ven 15/511:35
LGW
-
SAI
2 stops39h 10m
Multiple Airlines
lun 1/621:10
SAI
-
LGW
2 stops47h 50m
Multiple Airlines
Deal found 14/1£600
dom 1/307:25
STN
-
SAI
3 stops25h 40m
Multiple Airlines
dom 8/318:10
SAI
-
STN
2 stops35h 05m
Multiple Airlines
Deal found 15/1£610

Cheapflights 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, Cheapflights users made 858,174 searches. Data last updated 16 gennaio 2026.
Use the filters below to find and compare flights from London to Siem Reap that are best for you.

Fly from

London

Fly to

Siem Reap

Route

Depart

Return

Price

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

mer 18/2

10:30-18:05

2 stops24h 35m

Siem Reap–Angkor Intl

lun 23/3

19:05-14:00

2 stops25h 55m

£540

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

mar 17/3

19:25-18:45

2 stops16h 20m

Siem Reap–Angkor Intl

mar 16/6

09:40-21:45

2 stops18h 05m

£547

LondonSiem Reap

LHR - SAI

LHRSAI

London Heathrow

ven 15/5

13:40-18:45

2 stops23h 05m

Siem Reap–Angkor Intl

mar 2/6

09:40-07:55

2 stops28h 15m

£559

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

mer 11/3

10:30-18:05

2 stops24h 35m

Siem Reap–Angkor Intl

ven 27/3

19:05-14:00

2 stops25h 55m

£566

LondonSiem Reap

LCY - SAI

LCYSAI

London City

gio 14/5

19:15-09:40

2 stops32h 25m

Siem Reap–Angkor Intl

mar 2/6

10:30-08:40

2 stops28h 10m

£579

LondonSiem Reap

LCY - SAI

LCYSAI

London City

ven 15/5

19:15-18:45

2 stops41h 30m

Siem Reap–Angkor Intl

mar 2/6

09:40-08:40

2 stops29h 00m

£588

LondonSiem Reap

STN - SAI

STNSAI

London Stansted

dom 1/3

07:25-16:05

3 stops25h 40m

Siem Reap–Angkor Intl

dom 8/3

18:10-22:15

2 stops35h 05m

£610

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

ven 15/5

11:35-08:45

2 stops39h 10m

Siem Reap–Angkor Intl

lun 1/6

21:10-06:40

3 stops39h 30m

£613

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

ven 15/5

09:25-18:45

2 stops27h 20m

Siem Reap–Angkor Intl

mar 2/6

09:40-08:20

2 stops28h 40m

£625

LondonSiem Reap

LGW - SAI

LGWSAI

London Gatwick

gio 14/5

09:25-18:45

2 stops27h 20m

Siem Reap–Angkor Intl

mar 2/6

09:40-08:20

2 stops28h 40m

£625

Flights are sorted by cheapest return flights first.

Deals found on 15/1

Showing 1-10 of 60 results
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Best time to book a flight from London to Siem Reap

Have a flexible travel schedule? Discover the best time to fly to Siem Reap from London with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from London to Siem Reap

How far ahead should I book a flight from London to Siem Reap?

Use this chart to determine the optimal time to book a return flight from London to Siem Reap. Price data was last updated on 9 January 2026.

The best time to book flights from London to Siem Reap is 65 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from London to Siem Reap?

Currently, March is the cheapest month in which you can book a flight from London to Siem Reap (average of £572). Flying from London to Siem Reap in August is currently the most expensive (average of £896). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost for a return flight from London to Siem Reap?

What’s the top stopover airport for flights from London to Siem Reap?

Share of one-stop return flights from London to Siem Reap chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Singapore (SIN) – chosen by Cheapflights users on 69% of one-stop itineraries from London to Siem Reap on Cheapflights.

What’s the cheapest stopover airport for flights from London to Siem Reap?

Average return fare for one-stop flights from London to Siem Reap, chosen by Cheapflights users in the past 12 months, with the same stopover each way.

Hanoi (HAN) is the most affordable one-stop option, with an average return flight price of £692.

What’s the fastest stopover option from London to Siem Reap?

Shortest average travel time for one-stop one-way flights from London to Siem Reap, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.

Flights via Bangkok (BKK) have the shortest average one-way travel time for one-stop routes: 14h 00m.

Which airport typically offers the quickest stopover for flights from London to Siem Reap?

Average stopover duration for one-stop one-way flights from London to Siem Reap, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Bangkok (BKK) offer the fastest connection on this route, with an average stopover time of 1h 54m.

Reviews of airlines servicing Siem Reap

Get insights into the airlines that provide service to Siem Reap. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Siem Reap. Reviews last updated 16 gennaio 2026.
Read through reviews of airlines operating flights from London to Siem Reap, such as Singapore Airlines, Thai Airways, andVietnam Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Singapore Airlines
8.1
Very Good
1,431 reviews
Check prices

Entertainment

8.0

Boarding

8.3

Comfort

8.0

Crew

8.6

Overall

8.1

Food

7.8

Reviews

1 / 20
10.0
Excellent

Juliet,Oct 2025

PUS - SIN

Very kind staff to arrange my luggage and really appreciate all help.
Singapore Airlines
8.1
Very Good
1,431 reviews
Singapore Airlines
8.1
Very Good
1,431 reviews
Check prices

Entertainment

8.0

Boarding

8.3

Comfort

8.0

Crew

8.6

Overall

8.1

Food

7.8

Reviews

1 / 20
10.0
Excellent

Juliet,Oct 2025

PUS - SIN

Very kind staff to arrange my luggage and really appreciate all help.
Thai Airways
7.8
Good
378 reviews
Singapore Airlines
8.1
Very Good
1,431 reviews
Check prices

Entertainment

8.0

Boarding

8.3

Comfort

8.0

Crew

8.6

Overall

8.1

Food

7.8

Reviews

1 / 20
10.0
Excellent

Juliet,Oct 2025

PUS - SIN

Very kind staff to arrange my luggage and really appreciate all help.
Vietnam Airlines
7.6
Good
220 reviews
Singapore Airlines
8.1
Very Good
1,431 reviews
Check prices

Entertainment

8.0

Boarding

8.3

Comfort

8.0

Crew

8.6

Overall

8.1

Food

7.8

Reviews

1 / 20
10.0
Excellent

Juliet,Oct 2025

PUS - SIN

Very kind staff to arrange my luggage and really appreciate all help.
British Airways
6.7
Okay
7,676 reviews
Singapore Airlines
8.1
Very Good
1,431 reviews
Check prices

Entertainment

8.0

Boarding

8.3

Comfort

8.0

Crew

8.6

Overall

8.1

Food

7.8

Reviews

1 / 20
10.0
Excellent

Juliet,Oct 2025

PUS - SIN

Very kind staff to arrange my luggage and really appreciate all help.

Related info for your journey

Find useful and relevant information for your journey from London to Siem Reap. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Siem Reap from London?

    Located just 24.7 mi from the city center, Siem Reap–Angkor Intl is the airport most travelers will use when flying to Siem Reap from London. Booking flights from London to Siem Reap–Angkor Intl (SAI) should be relatively easy as there are 0 daily inbound flights from London from 5 different airlines.

  • How long is the flight from London to Siem Reap?

    A quick flight from London to Siem Reap can take about 20h 20m. SWISS provides one of the quickest options available for as low as £626. London and Siem Reap are separated by a distance of 6106 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the cheapest airlines flying from London to Siem Reap round-trip?

    Our cheapest airline available from London to Siem Reap is Austrian Airlines. Our recent data shows that you can find tickets from as low as £540 on this airline. Additional options worth looking into are Vietnam Airlines and Singapore Airlines, starting at £616 and £667 round-trip. Austrian Airlines is priced at 35% lower than the current average price of a flight leaving 3 months from now.

  • What are the most popular routes from London to Siem Reap?

    When deciding which route to take from London to Siem Reap consider London Heathrow - Siem Reap–Angkor Intl, London Gatwick - Siem Reap–Angkor Intl or London City - Siem Reap–Angkor Intl as they are the most popular.

  • Can I find deals for flights from London to Siem Reap that include hotel bookings?

    Yes. In addition to deals on London to Siem Reap flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from London to Siem Reap?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Siem Reap.

  • Can I find deals for business class flights from London to Siem Reap?

    Yes. Cheapflights offers flight deals from London to Siem Reap by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from London to Siem Reap?

    Currently, March is the cheapest month in which you can book a flight from London to Siem Reap (average of £572). Flying from London to Siem Reap in August is currently the most expensive (average of £896). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Top 5 airlines flying from London to Siem Reap

Discover the top 5 airlines that operate flights from London to Siem Reap. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 16 gennaio 2026.
AirlineCheapestAverageFlexibilityOn-time
Austrian AirlinesCheapest£540Average£691FlexibilityNo cancel feeOn-time78%
Search Austrian Airlines flights
Vietnam AirlinesCheapest£616Average£720FlexibilityNo cancel feeOn-time81%
Search Vietnam Airlines flights
Singapore AirlinesCheapest£667Average£905FlexibilityNo cancel feeOn-time81%
Search Singapore Airlines flights
LufthansaCheapest£734Average£769FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
Thai AirwaysCheapest£861Average£948FlexibilityNo cancel feeOn-time77%
Search Thai Airways flights

Fly with Cheapflights

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How does Cheapflights help users find flights from London to Siem Reap?

When you search for this flight from London to Siem Reap, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from London to Siem Reap?

Cheapflights helps you find that perfect flight to Siem Reap from London by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from London to Siem Reap with no change fees?

Need flexible booking options for your flight to Siem Reap from London? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from London to Siem Reap become cheaper?

Of course! You can now track prices for flights from London to Siem Reap and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.

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