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Cheap flights from London Heathrow Airport to Siem Reap, Cambodia

LHR — SAI
9 Jul — 16 Jul1
1 adult

Cheap flight deals from Heathrow to Siem Reap

Discover tips and strategies to find the most affordable flight options for your journey from Heathrow (LHR) 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 4 July 2025.

Popular in

August

Cheapest in

May

Average price

£941
Highest demand for flights based on searches. 13% potential increase in price (£91 potential increase over avg. return price).
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Cheapest flight prices on average. 4% potential price decrease (£27 potential savings vs. average return price).
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Average for round-trip flights in July 2025
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Best time to book a flight from Heathrow to Siem Reap

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

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

Use this chart to determine the optimal time to book a return flight from Heathrow to Siem Reap. Price data was last updated on 27 June 2025.

The best time to book flights from London Heathrow Airport to Siem Reap is 41 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.

Related info for your journey

Find useful and relevant information for your journey from Heathrow 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 Heathrow?

    For a flight from London Heathrow to Siem Reap, you will be flying into 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 inbound flights from London Heathrow per day. 4 airlines have flights to Siem Reap–Angkor Intl from London Heathrow on a regular basis.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Heathrow 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.

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Top 4 airlines flying from Heathrow to Siem Reap

Discover the top 4 airlines that operate flights from Heathrow 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 4 July 2025.
AirlineCheapestAverageFlexibilityOn-time
Vietnam AirlinesCheapest£622Average£744FlexibilityNo cancel feeOn-time81%
Search Vietnam Airlines flights
Singapore AirlinesCheapest£644Average£720FlexibilityNo cancel feeOn-time81%
Search Singapore Airlines flights
LufthansaCheapest£749Average£762FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights
Thai AirwaysCheapest£801Average£932FlexibilityNo cancel feeOn-time77%
Search Thai Airways 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 Heathrow to Siem Reap?

When you search for this flight from Heathrow 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 Heathrow to Siem Reap?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Heathrow to Siem Reap.

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

Need flexible booking options for your flight to Siem Reap from Heathrow? 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 Heathrow to Siem Reap become cheaper?

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

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