£276 Find Cheap Flights from London to Siem Reap – Compare and Save

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 1/9. 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.
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1 adult, Economy, 0 bags

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Book Cheap London to Siem Reap Plane Tickets

 
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

Thu, 19 Nov - Thu, 3 Dec
Austrian Airlines Logo
06:00 - 18:45
LHR
-
SAI
29h 45m
2 stops
Austrian Airlines Logo
09:55 - 21:40
SAI
-
LHR
18h 45m
2 stops
£575Austrian Airlines
Fri, 27 Nov - Sat, 12 Dec
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
27h 30m
3 stops
China Eastern Logo
22:00 - 14:00
SAI
-
LGW
47h 00m
2 stops
£588China Eastern
Fri, 27 Nov - Sat, 12 Dec
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
27h 30m
3 stops
China Eastern Logo
22:00 - 06:30
SAI
-
LGW
39h 30m
3 stops
£588China Eastern
Wed, 28 Oct - Tue, 10 Nov
Austrian Airlines Logo
09:05 - 18:45
LHR
-
SAI
26h 40m
2 stops
Austrian Airlines Logo
19:25 - 08:20
SAI
-
LHR
19h 55m
2 stops
£612Austrian Airlines
Mon, 23 Nov - Mon, 7 Dec
Vietnam Airlines Logo
11:00 - 16:55
LHR
-
SAI
22h 55m
1 stop
Vietnam Airlines Logo
18:40 - 07:15
SAI
-
LHR
19h 35m
1 stop
£747Vietnam Airlines
Thu, 19 Nov - Thu, 3 Dec
Singapore Airlines Logo
13:00 - 15:55
LGW
-
SAI
19h 55m
1 stop
Singapore Airlines Logo
10:45 - 09:00
SAI
-
LGW
29h 15m
1 stop
£754Singapore Airlines
Thu, 12 Nov - Thu, 19 Nov
Singapore Airlines Logo
13:00 - 15:55
LGW
-
SAI
19h 55m
1 stop
Singapore Airlines Logo
10:45 - 09:00
SAI
-
LGW
29h 15m
1 stop
£772Singapore Airlines
Sun, 30 Aug - Wed, 30 Sep
Vietnam Airlines Logo
19:50 - 17:10
LHR
-
SAI
15h 20m
1 stop
Vietnam Airlines Logo
19:10 - 16:55
SAI
-
LHR
27h 45m
1 stop
£780Vietnam Airlines
Mon, 18 Jan - Mon, 1 Feb
Thai Airways Logo
11:50 - 08:45
LHR
-
SAI
13h 55m
1 stop
Thai Airways Logo
09:50 - 19:35
SAI
-
LHR
16h 45m
1 stop
£947Thai Airways
Sun, 8 Nov - Sun, 22 Nov
Thai Airways Logo
11:50 - 08:45
LHR
-
SAI
13h 55m
1 stop
Thai Airways Logo
09:50 - 19:35
SAI
-
LHR
16h 45m
1 stop
£950Thai Airways
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 to Region of 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 to Region of Siem Reap departing in November.

Flight prices are below average for this route right now.

Flights to Region of Siem Reap from London usually cost between £902 and £1,079 in November.
The lowest price found in the past 5 days was £575 on Austrian Airlines (19 Nov–3 Dec).

What is the cheapest month to fly from London 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 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 to Siem Reap is March, when tickets cost £686 (return) on average. On the other hand, the most expensive months are December and August, when the average cost of return tickets is £969 and £924 respectively.

Good to know - Cheap tickets from London to Siem Reap

Low season

July
Best time to beat the crowds (23% less expensive on average)
Most popular time to fly and prices are also 4% lower on average.

FAQs - booking Siem Reap flights

  • 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 from London to Siem Reap 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 from London to Siem Reap with an airline and back 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 from London to Siem Reap up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 4 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 1584 reviews
8.0Comfort
7.8Food
8.3Boarding
8.6Crew
8.1Entertainment
Airline reviews

Limited food options. I dont like chicken or even fish but that’s the only option. Sad to say not impress

6.0 GoodDreiTen, Jun 2026
MNL - SIN
Read more Singapore Airlines reviews

Limited food options. I dont like chicken or even fish but that’s the only option. Sad to say not impress

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

I had ordered vegetarian food. What I was presented was extremely dissatisfying and not up to the mark. I pretty much did not eat entire 19 hours. For.an airline voted as best in business, it was extremely disappointing. Seats were not comfortable to sleep. Entertainment system didn’t have much choice. WiFi didn’t work for more than half the time. Cabin crew were also difficult to understand. A bit of diversity like Emirates crew would go a long way.

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

Service excellent would chose Singapore airlines as my first choice

Crews are not allowed to perform any service whenever the captain deems there’s a chance of turbulence. Even if it is perfectly smooth air.

They ran out of food for breakfast They did not offer tea or coffee The staff appeared very inexperienced The cabin was very cold, even with a blanket

Perfect experience from boarding through to leaving the flight, comfortable and personalised service from all staff, highly recommended

The male traveller seated in the row in front diagonally opposite my husbands seat across the aisle as soon as the seatbelt sign went off moved across the aisle into the seat in front of my husband for the entire journey from London to Singapore he had his seat reclined and pushed back and the seat touching my husbands knees for the entire journey from London to Singapore. very uncomfortable for my husband.

More Baggage limit Alternative of virtual check in at airport , prefer personal touch with “real person”check in counter for baggage drop

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.

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.

Could have been better. I prefer Thai airlines only but it hasnt been reliable.

It was good overall. At 6 foot 1 it's hard to say anything seat on a flight is comfortable but it would be nice to have more legroom. The meals were good but would have liked to get wine much sooner.

Extra seat belt across the chest 10 minutes before taking off and 15 minutes before landing seemed excessively safe.

The transfer from Domestic and International was a bit confusing but I am easily confused. I did not eat any food, but the food on the other leg was decent. It was nice they turned the lights off on the night flight. The plane was in good shape, but was a little cramped in economy and I am small. They gave me a customs form to fill out and nobody looked at it as I went through customs. Not a bad flight.

Check in was a disaster. 90 minutes and only 2 economy check in desks open. Had to rush to catch the flight.

I couldnt go on this flight and lost all my money over 1,000 UK Pounds as my visa to Myanmar was not accepted :(

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

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

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.

Lovely staff, comfortable seats. Transit time was short but they had great processes in place to get us on the plane.

2 hours delay, time changes started already 2 days before the flight

Ensure there is a choice of food for all customers and also enough food

An excellent airline; polite and courteous cabin crew, excellent meal and drink service. Highly recommended.

No space in between the seats as per them the average height of human is 5’3” and weight as 55, so seats are designed as per the same. Also, the aircraft was dirty and full of insects

Flight was good but they cancelled return direct flight so they provide us connecting flight through hanoi

The most attentive crew and although we were a little late leaving ( missing passenger) flight experience more than compensated . Best flight attendants I have flown with in 50 years !!

My flight from Zurich to London was delayed 2hours and 45minutes. It was awful.

Not enough food for a 4 hour trip…Lack of entertainment and with no WIfi accessibility I didn’t figure it out how to access free WiFi

Not good because in this cancelled and then rebooked flight BA put me and my husband in both middle seats when we were originally seated together in original flight and i was in aisle. I hate sitting in the middle. BA food needs to be better. It was just ok. Thanks though to screw and everyone one for safe flight

Crew members were thorough in checking seatbelts and whatnot which makes me feel cared for because passenger safety is a main concern.

I was sent an email that said my card payment was not verified. When I spoke to an agent , he said my card was not verified and the flight I thought I had to booked was no longer available so I booked another flight on another airline(United). Later I got flight updates , etc., concerning my supposed first flight. So if I was charged for this flight on British Airways/American airlines, I need a refund.

The crew made it a great flight. They were friendly and attentive. They made me want to fly British Airways again.

BA has not been handling priority luggage with any special priority. This time our luggage was distinctly very slow to arrive, well after the first half of items to arrive. Business class flights cost a lot and it would be nice to have that reflected in the speed of baggage handling! (I note that this has worsened in our long experience of BA.) On a different note, we spent 2.5 hours on the plane after landing because of an airport mishap at Boston Logan. The pilot provided reasonably frequent update but more could have been done to ensure passenger comfort, such as more beverage and maybe snack services.

I purchased premier economy seats but I was seated one row off and was sitting in economy my bottle of water and cookie did not compare to the menus handed OP it in premier.

I understand and don't want food on a short trip, but tea and coffe (at least 1 cup) should be free. Nevertheless there was water available and the crew was nice.

Food is horrible. Flight was good and the staff were mostly men.

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

Cabin class types available on flights to Siem Reap

Cabin classes available on flights to Siem Reap. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.