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Cheap flights from Siem Reap, Cambodia to London Heathrow Airport from £244

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 11/5. Fares are subject to change and may not be available on all flights or dates of travel.
SAI — LHR
16 Mar — 23 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Siem Reap to Heathrow

Enter your travel dates to find the best prices.

Cheapest flights from Siem Reap to Heathrow
Explore the most affordable flight options available from Siem Reap to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 14 February 2026.

Thu 19/309:50
SAI
-
LHR
1 stop16h 45m
Thai Airways
Thu 19/321:35
LHR
-
SAI
1 stop28h 10m
Thai Airways
Deal found 12/2£996
Thu 19/309:55
SAI
-
LHR
1 stop16h 10m
Multiple Airlines
Thu 19/321:20
LHR
-
SAI
3 stops35h 00m
Multiple Airlines
Deal found 12/2£1,027
Thu 19/209:50
SAI
-
LHR
1 stop16h 45m
Multiple Airlines
Thu 19/222:00
LHR
-
SAI
2 stops40h 10m
Multiple Airlines
Deal found 14/2£1,149
Thu 19/209:50
SAI
-
LHR
1 stop16h 45m
Thai Airways
Thu 19/221:35
LHR
-
SAI
1 stop28h 10m
Thai Airways
Deal found 14/2£1,737

Find flight deals from Siem Reap to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from Siem Reap (SAI) to Heathrow (LHR). 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 14 February 2026.

Round-trip from

£996

One-way from

£244
Thai Airways
  • Thai Airways
  • 19/3-19/3
  • 2 total stops
  • 44h 55m total
  • Siem Reap to London
Search Deals
China Eastern
  • China Eastern
  • 11/5
  • 2 total stops
  • 27h 30m total
  • Siem Reap to London
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from Siem Reap to Heathrow 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 14 February 2026.
Use the filters below to find and compare flights from Siem Reap to London Heathrow Airport that are best for you.

Fly from

Siem Reap

Fly to

Heathrow

Route

Depart

Return

Price

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 19/3

09:50-19:35

1 stop16h 45m

London Heathrow

Thu 19/3

21:35-08:45

1 stop28h 10m

£996

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 19/3

09:55-19:05

1 stop16h 10m

London Heathrow

Thu 19/3

21:20-15:20

3 stops35h 00m

£1,027

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Mon 11/5

21:10-18:40

2 stops27h 30m

£244

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Sat 7/3

22:00-17:30

2 stops26h 30m

£244

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Wed 20/5

21:10-18:40

2 stops27h 30m

£249

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Mon 30/3

21:10-18:40

2 stops51h 30m

£256

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Tue 3/3

22:00-17:30

2 stops50h 30m

£256

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 5/3

22:00-17:30

3 stops50h 30m

£256

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Wed 20/5

19:05-19:30

3 stops54h 25m

£272

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Sat 9/5

14:55-20:00

3 stops35h 05m

£286

Flights are sorted by cheapest return flights first.

Deals found on 12/2

Best time to book a flight from Siem Reap to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Siem Reap 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.

Related info for your journey

Find useful and relevant information for your journey from Siem Reap to Heathrow. 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 from for flights from Siem Reap to London Heathrow?

    For a flight from Siem Reap to London Heathrow, you will be flying from Siem Reap–Angkor Intl. Siem Reap–Angkor Intl (SAI) is just 24.7 mi from the center of the city. Siem Reap–Angkor Intl is the only Siem Reap airport and it handles 0 outbound flights to London Heathrow per day. 0 airlines have flights to London Heathrow from Siem Reap–Angkor Intl on a regular basis.

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

    Airlines like Thai Airways fly from Siem Reap to London Heathrow Airport in about 16h 45m. The time it takes to get you to your destination can typically vary by up to . Airlines will cover a distance of 6106 mi.

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

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

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

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

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

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

See more FAQs

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Croydon
Luton
Wembley
Northampton
Gatwick
Slough
Hounslow
Ilford
Hayes
Brentford
Colchester
Watford
Guildford
Chelmsford
Eastbourne
Crawley
Kingston upon Thames
Ipswich
Swindon

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Siem Reap to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
Siem Reap to Gatwick flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

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

Cheapflights makes it easy to find Siem Reap to Heathrow flights by helping our users search from 900+ travel sites for deals. We also provide you with filters for cabin, price, airline, airports, number of stops, and many more to narrow down that perfect flight.

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

Cheapflights helps you find that perfect flight to Heathrow from Siem Reap 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 Siem Reap to Heathrow with no change fees?

Cheapflights does show flights with no change fees to all users. To see these options for flights from Siem Reap to Heathrow, users can toggle the no change fees filter when performing a flight search.

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

Not ready to book yet? You can track prices for flights from Siem Reap to Heathrow on Cheapflights with our Price Alert feature and get notified when better prices are available.

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