LHR - SAI

£424 Find Cheap Flights from London to Siem Reap

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from London to Siem Reap departing on 20/5. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Siem Reap

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from London to Siem Reap, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from London to Siem Reap, as well as popular online travel agencies
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Everything you should know

Cheapest return fare
£586
Typical prices: £813-£753
Etihad Airways
Sun 14/6Tue 30/6
LHR - SAI • 2 stops
Cheapest one-way flight
£376
Typical prices: £395-£475
Etihad Airways
Wed 20/5
LHR - SAI • 2 stops
Top airlines
Cheapest • from £586 (return)
Best reviews • 8.2 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Direct flights
Not available
There are currently no direct flights between London and Siem Reap. You’ll need at least 1 connection.
Insights
Insights
Insights
Insights
Top stopover airports
Cheapest • Avg £745 (return)
Shortest trip • 13h 55m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 16% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Siem Reap!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from London to Siem Reap (LHR-SAI)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from London to Siem Reap that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent return flight deals from London to Siem Reap

Sun, 14 Jun - Tue, 30 Jun
Etihad Airways Logo
09:30 - 11:15
LHR
-
SAI
19h 45m
2 stops
Etihad Airways Logo
19:20 - 18:45
SAI
-
LHR
29h 25m
2 stops
£586Etihad Airways
Thu, 28 May - Thu, 18 Jun
Etihad Airways Logo
09:30 - 16:55
LHR
-
SAI
25h 25m
2 stops
Etihad Airways Logo
15:10 - 15:05
SAI
-
LHR
29h 55m
2 stops
£606Etihad Airways
Thu, 28 May - Thu, 18 Jun
Etihad Airways Logo
09:30 - 16:55
LHR
-
SAI
25h 25m
2 stops
Etihad Airways Logo
15:10 - 12:45
SAI
-
LHR
27h 35m
2 stops
£624Etihad Airways
Thu, 28 May - Thu, 18 Jun
Etihad Airways Logo
09:30 - 11:15
LHR
-
SAI
19h 45m
2 stops
Etihad Airways Logo
15:10 - 12:45
SAI
-
LHR
27h 35m
2 stops
£642Etihad Airways
Sat, 12 Sep - Wed, 23 Sep
SWISS Logo
18:40 - 18:55
LHR
-
SAI
42h 15m
2 stops
SWISS Logo
09:40 - 17:50
SAI
-
LHR
38h 10m
2 stops
£689SWISS
Sat, 12 Sep - Thu, 24 Sep
Multiple Airlines Logo
21:45 - 11:15
LHR
-
SAI
31h 30m
2 stops
Multiple Airlines Logo
09:40 - 15:20
SAI
-
LHR
35h 40m
2 stops
£725Multiple Airlines
Mon, 29 Jun - Mon, 20 Jul
Etihad Airways Logo
09:30 - 11:15
LHR
-
SAI
43h 45m
2 stops
Etihad Airways Logo
19:35 - 15:05
SAI
-
LHR
25h 30m
2 stops
£727Etihad Airways
Tue, 14 Jul - Tue, 11 Aug
Etihad Airways Logo
09:30 - 17:50
LHR
-
SAI
26h 20m
2 stops
Etihad Airways Logo
15:10 - 15:05
SAI
-
LHR
29h 55m
2 stops
£735Etihad Airways
Tue, 8 Sep - Tue, 15 Sep
Austrian Airlines Logo
19:30 - 18:55
LHR
-
SAI
17h 25m
2 stops
Austrian Airlines Logo
19:35 - 08:20
SAI
-
LHR
18h 45m
2 stops
£755Austrian Airlines
Sun, 14 Jun - Tue, 30 Jun
Multiple Airlines Logo
09:30 - 14:20
LHR
-
SAI
22h 50m
2 stops
Multiple Airlines Logo
15:10 - 08:00
SAI
-
LHR
22h 50m
3 stops
£760Multiple Airlines
Booking Insights

KAYAK’s insights & trends for London to Siem Reap flights

Get data-powered insights and trends into flights from London to Siem Reap to help you find the cheapest flights, the best time to fly and much more.

How much is a return flight from London Heathrow Airport to Siem Reap?

This analysis is based on the cheapest return trip price found on KAYAK in the last 12 months by searching for a flight from London Heathrow Airport to Siem Reap departing in June.

What is the cheapest month to fly from London Heathrow Airport to Siem Reap?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from London Heathrow Airport to Siem Reap, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from London Heathrow Airport to Siem Reap is June, where tickets cost £667 (return) on average. On the other hand, the most expensive months are August and July, where the average cost of round-trip tickets is £1,012 and £899 respectively.

Good to know - Cheap tickets from London to Siem Reap

Low seasonJuly
Cheapest flight£376
Best time to beat the crowds but there is an average 12% increase in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from London to Siem Reap

When to book flights from London to Siem Reap

Are your dates flexible? Find out the best times to travel from London to Siem Reap based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated return price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or returns with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking London to Siem Reap flights

  • What is the cheapest flight from London Heathrow Airport to Siem Reap?

    In the last 3 days, the lowest price for a flight from London Heathrow Airport to Siem Reap was £376 for a one-way ticket and £586 for a return.

  • Which airports will I be using when flying from London to Siem Reap?

    London and Siem Reap are both served by 1 main airport. You will leave London from London Heathrow and will be arriving at Siem Reap–Angkor Intl.

  • Which aircraft models fly most regularly from London to Siem Reap?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from London to Siem Reap?

    SkyTeam, and Star Alliance are the airline alliances operating flights between London and Siem Reap, with SkyTeam being the most commonly used for this route.

  • Which is the best airline for flights from London to Siem Reap, Singapore Airlines or Thai Airways?

    The two airlines most popular with KAYAK users for flights from London to Siem Reap are Singapore Airlines and Thai Airways. With an average price for the route of £750 and an overall rating of 8.2, Singapore Airlines is the most popular choice. Thai Airways is also a great choice for the route, with an average price of £931 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from London to Siem Reap?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from London to Siem Reap.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from London to Siem Reap?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Siem Reap from London is likely to change within 7 days, so travellers know whether to wait or book now.

  • What is the Hacker Fare option on flights from London to Siem Reap?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly to Siem Reap with an airline and back to London with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from London to Siem Reap?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Siem Reap from London up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines flying from London to Siem Reap

 
See real verified KAYAK customer reviews for airlines flying from London to Siem Reap. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from London to Siem Reap? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.2
Singapore AirlinesOverall score based on 1510 reviews
8.3Boarding
8.0Entertainment
7.8Food
8.6Crew
8.0Comfort
Airline reviews

Food was terrible , uncomfortable seats, WiFi did not work, will never fly Singapore again.

2.0 MediocreAnonymous, May 2026
LAX - NRT
Read more Singapore Airlines reviews

Food was terrible , uncomfortable seats, WiFi did not work, will never fly Singapore again.

Really great service throughout and the food was really nice. I can highly recommend thank you very much.

Overall the airline tried to give excellent service. The wheelchair service was bad at SFO. My baggage was also delayed but I thank them for taking the trouble to find it and deliver it to my home.

First time flying with Singapore airlines and I’ll give them two thumbs up 👍 👍

I find it was a bit hot before take off. If there is a way to improve the airflow it would be great

No frills airline with minimal leg room and no entertainment

Best service airline. The cabin crew is attentive and friendly. Inflight entertainment system is good

I was in a middle seat where I felt a bit too cramped otherwise the trip was good

Airline should consider adding a small meal at the last leg of the flight, right now there is 7 hours of no meal break.

Crew and service excellent. 2 hour delay for takeoff. SQ app showed flight on time.

HAVING ANNOUNCEMENTS FOR PEOPLE TO BOARD ACCORDING TO GROUP IS ESSENTIAL N ENSURING N CUTTING OF QUEUES, EXCEPT FOR PRIORITY CLASS PASSENGERS ON A SEPARATE Q

We still get drinks and a snack. Love the gift bags too.

business class is old but still done very well by the team.

Excellent airline. The plane was clean and the staff were very attentive

Good experience although the boarding gate is at the terminal extension hence need to leave lounge to head over earlier.

Thai Royal First is very good. Easy check in , Private room in the first class lounge and escort from ticketing to the plane. Once on board crew was very polite, food was outstanding, and the ride was smooth as silk. Restrooms were especially clean. Great Experience

I'm not interested in improving the airline. Therefore, I won't explain this in more detail. Next time I'll try a different one.

The flight (boarding) was delayed by 40-50 minutes and there was very crowed. They need to improve on the timeliness & boarding process. (They asked passenger to board in groups, but the 2nd group was standing there waiting for 20 minutes!). However, services from the crew was very good, also the food was good as well. I also found the legroom was quite comfortable.

Need to improve on punctuality. My flight was delayed by 1 hour.

Seats were uncomfortable and the vegetarian meal was awful. Some of the entertainment didn't work.

I thought I already provided this feedback. 12 hours with no wifi is unacceptable. Lay flat is nice but a bit cramped.

The vietnam airlines app was not able to allow checkin with the confirmation nor with the ticket number. This led to quite a bit of consternation. Speaking with a colleague from Hanoi, he did tell me that their app is not the best. It may be best to inform travelers to only use the link and to plan on checking in at the airport for this airline. The check-in was very easy and the staff were excellent.

flight departure was late, with no updates on status of departure

The aircraft was little tired but the food and service was outstanding

It was ok, it felt more like an internal flight than an international flight so I guess expected a slightly better standard. Nothing really wrong with it but there was no inflight entertainment. Food and service was good.

This was our fourth domestic flight with Vietnam Airlines, and once again we found the experience very suitable. Check-in was easy and efficient. They did take our carry-on luggage, but that was fine. I’m actually happy not to deal with it on such a short flight. The flight was just over an hour, departed on time, and we climbed above the clouds into a beautiful sunset. Even on such a short flight, they served water, which we appreciated. Luggage came out into carousel in Nha Trang in good time and off we went to meet our GRAB. Also, Vietnam Airlines have easy to locate ground level offices in cities and towns where you can get assistance with staff. I liked this service as we did go visit one in Nha Trang. We would definitely recommend Vietnam Airlines and wouldn’t hesitate to fly with them again.

Really good 👍 This was our first time flying with Vietnam Airlines. It was a short domestic flight, so no meal service, but boarding was organized and the flight departed and arrived on schedule. The flight attendants were professional and neatly presented. All in all, a very good first experience. We would recommend Vietnam Airlines.

We flew with their partner VESCO on a small plane, it was a really good flight. There was no food or entertainment as it’s a one hour hopper flight.

The flight boarded and departed pretty much on time as it’s just a one hour flight there is no food or entertainment so I marked that at the neutral but they do offer water and I’m sure if you needed some food you could bring your own onboard. This was our third internal flight with Vietnam Airways and I recommend them.

This is a very short commuter flight, so there is no food or flight entertainment. Hence, I marked it in the neutral flight left on time. The plane was full pretty much and it was a pretty easy flight overall very good.

Accommodate the passangers at the gates. They only allow groups 1-3 to sit near/at the gate. We had to wait 3 HRs an had to look for a seat far away from the gate. Other than that was like other Airports.

Last few years I didn't not have great experience with United Airlines.

Short flight. Bare bones and kinda seeming like an older plane. But got me there on time and that's what counts. Perfectly fine flight all the way from start to finish.

My Austrian Air flight from Montenegro to Vienna was delayed by three hours because their plane de-icer was broken and they had to wait for the sun to come up before the ice could melt. This meant we missed our United flight altogether. So I can't speak about United, but I was not impressed by Austrian Air. They made us check in two carry on bags for a 60% full flight, and the bags didn't find us in the US for ten days. The re-routing they arranged included an extra leg, a midnight taxi ride across New Jersey and New York, and a five hour sleep in a hotel. Not impressed.

Most of the crew members were rude, flight arrived late and we missed our connecting flight, they damaged my friends suitcase so badly that two wheels had been destroyed.

Excellent flight. The crew was exceptionally attentive and organized. Attention to details is unmatched.

I did wish they would give us the entire little bottle Bailey's instead of just have 1/2 bottle at a time

My layover in Vienna was supposed to be 35 minutes but because my flight was canceled I had to wait in the airport for an additional 8 hours.

Very limited legroom in a 10 hour flight.very old plane.

The flight was delayed for 30 minutes with no apparent reason. There is no entertainment at all, and no USB or electric outlets for charging your phone or tablet.

Original Lufthansa flights were canceled and the alternative route that was offered required cab transfer in New York from JFK to Newark at my own expense. Who can refund these $218?

Flight map did not work. Crew was great, food was good, plane took off on time and landed early. That's all I can ask.

We exited from a plane from LAX TO MUC containing 853 passengers. Passport control was packed and very slow as they fingerprinted and photgraphed everyone. After finally getting though we ran to the gate listed on our boarding pass. We made it just as boarding was suppost to begin. No one was there. We started running again and found a Lufthansa gate open and spoke with them. We were told the gate had changed and they called the correct gate that we were coming. We started running again, but needed to wait for the train to get to the correct terminal. Running again we made it to the gate. The plane was still there but they said it was too late. So we went to the Lufthansa help desk, they told us it was our fault for missing our flight and that if we didn't buy a new ticket from them for €256 each our return trip to the states would be cancelled. Needless to say this was very disapointing to find out on the day before Christmas that we had to pay an extra €512 to complete our trip we had already paid $3344 for. We were left with no choice. No Christmas spirit there. Unhappy custumers.

Paid for exit row at the back of the plane. Window seat with lots of leg space. Food was inedible (as usual). Brought my own.

in athens they helped me with my dogs and they solved all my issues excellent service outstanding

The flight and crew were good. The customer experience on the ground could have been better. We had to reschedule our flight because of a delay on the previous flight. The attendants working the desk in Washington DC were not helpful. They told us to scan a QR code and that would get us rebooked. Why couldn't two people standing at their computers do this? We had to chat with someone to get everything figured out. It was extremely confusing.

Efficiency of staff, and comfort and cleanliness of aircraft was all great. Maybe a hot drink without payment at that time in the morning would be good!

The plane was late (as was my flight out from Birmingham the day before)

Everything well done and customer oriented There entertainment system is difficult to navigate

The flight was delayed by an hour. Made the connection uncomfortably tight.

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

Information on your arrival and departure airports