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Cheap flights from Siem Reap, Cambodia to London Heathrow Airport from £313

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 14/5. Fares are subject to change and may not be available on all flights or dates of travel.
SAI — LHR
24 Apr — 1 May1
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 25 March 2026.

Thu 1/1009:40
SAI
-
LHR
2 stops27h 15m
Multiple Airlines
Thu 29/1021:00
LHR
-
SAI
3 stops41h 00m
Multiple Airlines
Deal found 25/3£746
Tue 6/1009:40
SAI
-
LHR
2 stops27h 15m
Multiple Airlines
Tue 20/1017:30
LHR
-
SAI
2 stops34h 10m
Multiple Airlines
Deal found 25/3£781
Thu 1/1010:30
SAI
-
LHR
1 stop35h 15m
Singapore Airlines
Thu 29/1010:40
LHR
-
SAI
1 stop22h 15m
Singapore Airlines
Deal found 25/3£925

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 25 March 2026.
Use the filters below to find and compare flights from Siem Reap to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest one-way

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 14/5

13:05-06:55

2 stops23h 50m

£313

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Sun 5/4

15:35-06:25

2 stops44h 50m

£373

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 16/4

14:50-12:45

2 stops27h 55m

£393
Fastest single journey

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 16/4

23:50-14:25

2 stops20h 35m

£394

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Sun 17/5

13:05-18:40

2 stops35h 35m

£394

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Sat 11/4

23:50-14:25

2 stops20h 35m

£396

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Tue 7/4

23:50-14:25

2 stops20h 35m

£396

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Thu 14/5

11:00-16:35

1 stop35h 35m

£425

Siem ReapLondon

SAI - LHR

SAILHR

Siem Reap–Angkor Intl

Sun 24/5

18:05-17:05

1 stop29h 00m

£468

Flights are sorted by cheapest return flights first.

Deals found on 22/3

Sorted by cheapest first

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.

  • 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
Wembley
Croydon
Northampton
Hounslow
Luton
Gatwick
Slough
Ilford
Hayes
Brentford
Colchester
Eastbourne
Guildford
Watford
Kingston upon Thames
Romford
Ipswich
Swindon
Bedford

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

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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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