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Cheap flights from Siem Reap, Cambodia to London Heathrow Airport from £248

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 26/11. Fares are subject to change and may not be available on all flights or dates of travel.
SAI — LHR
11 Sep — 18 Sep1
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 12 August 2026.

Thu 13/817:55 -
2 stops29h 45m
Thu 3/921:45 -
2 stops31h 30m
Deal found 9/8£792
Fri 18/1219:25 -
2 stops44h 45m
Fri 1/110:20 -
2 stops39h 55m
Deal found 10/8£826
Wed 16/1209:55 -
2 stops39h 15m
Fri 1/120:55 -
2 stops29h 20m
Deal found 10/8£846
Fri 28/821:10 -
2 stops27h 30m
Thu 10/908:45 -
2 stops28h 10m
Deal found 11/8£851
Fri 18/1219:25 -
2 stops44h 45m
Wed 30/1216:15 -
2 stops37h 25m
Deal found 10/8£852
Mon 21/1209:55 -
2 stops39h 15m
Fri 1/120:55 -
2 stops29h 20m
Deal found 10/8£853
Wed 16/1209:55 -
2 stops39h 15m
Wed 30/1220:55 -
2 stops29h 20m
Deal found 10/8£854
Tue 15/1209:55 -
2 stops27h 45m
Wed 30/1220:55 -
2 stops32h 45m
Deal found 10/8£862
Wed 16/1209:55 -
2 stops39h 15m
Tue 29/1219:20 -
2 stops54h 55m
Deal found 10/8£868
Sun 20/1209:55 -
2 stops27h 45m
Thu 31/1220:55 -
2 stops32h 45m
Deal found 10/8£870
Thu 17/1219:25 -
2 stops20h 45m
Thu 31/1210:20 -
2 stops19h 20m
Deal found 10/8£871
Tue 15/1220:30 -
1 stop17h 45m
Fri 1/111:00 -
1 stop25h 40m
Deal found 10/8£872

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 12 August 2026.

Round-trip from

£826

One-way from

£248
Finnair
  • Finnair
  • 18/12-1/1
  • 4 total stops
  • 84h 40m total
  • Siem Reap to London
Search Deals
26/11
  • 26/11
  • 2 total stops
  • 55h 05m 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 12 August 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 return flight

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Fri 28/8

21:10-18:40

2 stops27h 30m

London Heathrow

Thu 10/9

08:45-18:55

2 stops28h 10m

£851

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Mon 21/12

09:55-06:40

2 stops27h 45m

London Heathrow

Thu 31/12

20:55-09:15

2 stops29h 20m

£870

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Sat 19/12

20:30-07:15

1 stop17h 45m

London Heathrow

Fri 1/1

11:00-19:40

1 stop25h 40m

£872
Fastest return journey

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Mon 21/12

21:30-07:15

1 stop16h 45m

London Heathrow

Wed 30/12

11:00-19:40

1 stop25h 40m

£941

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Sun 20/12

17:55-07:15

1 stop20h 20m

London Heathrow

Thu 31/12

11:00-20:30

1 stop26h 30m

£941

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Thu 17/12

17:55-07:15

1 stop20h 20m

London Heathrow

Tue 29/12

11:00-20:30

1 stop26h 30m

£985

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Tue 15/12

20:30-07:15

1 stop17h 45m

London Heathrow

Thu 31/12

06:20-20:30

2 stops31h 10m

£1,071
Cheapest one-way

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Sat 17/10

19:05-19:20

2 stops54h 15m

£252

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Fri 16/10

19:05-19:20

2 stops30h 15m

£254

Siem ReapLondon

SAI Siem Reap–Angkor Intl - LHR London Heathrow

SAILHR

Siem Reap–Angkor Intl

Wed 19/8

19:05-20:00

2 stops54h 55m

£254

Flights are sorted by cheapest return flights first.

Deals found on 10/8

Showing 1-10 of 18 resultsSorted by cheapest first
1
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 Etihad Airways and Vietnam Airlines fly from Siem Reap to London Heathrow Airport in about 17h 45m. The time it takes to get you to your destination can typically vary by up to 10h. Airlines will cover a distance of 6106 mi. Both multi-stop and direct flights can be found to your destination and back.

  • 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
Hounslow
Milton Keynes
Luton
Gatwick
Wembley
Ilford
Slough
Hayes
Croydon
Colchester
Brentford
Eastbourne
Northampton
Watford
Southend-on-Sea
Swindon
Enfield
Kingston upon Thames
Southall
Poole

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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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