£267 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 10/5. 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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Flight Deals

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

Wed, 15 Apr - Wed, 10 Jun
Multiple Airlines Logo
11:35 - 08:45
LGW
-
SAI
39h 10m
2 stops
Multiple Airlines Logo
21:10 - 15:00
SAI
-
LGW
47h 50m
3 stops
£541Multiple Airlines
Wed, 15 Apr - Wed, 10 Jun
Multiple Airlines Logo
21:20 - 08:45
LHR
-
SAI
29h 25m
2 stops
Multiple Airlines Logo
21:10 - 18:40
SAI
-
LHR
27h 30m
2 stops
£569Multiple Airlines
Mon, 20 Apr - Fri, 15 May
China Eastern Logo
18:00 - 20:10
LGW
-
SAI
44h 10m
3 stops
China Eastern Logo
21:10 - 06:40
SAI
-
LGW
63h 30m
2 stops
£571China Eastern
Tue, 5 May - Fri, 12 Jun
China Eastern Logo
11:35 - 20:10
LGW
-
SAI
26h 35m
2 stops
China Eastern Logo
21:10 - 15:00
SAI
-
LGW
47h 50m
2 stops
£583China Eastern
Sun, 31 May - Tue, 9 Jun
SWISS Logo
08:45 - 18:45
LHR
-
SAI
28h 00m
2 stops
SWISS Logo
09:40 - 21:45
SAI
-
LHR
18h 05m
2 stops
£595SWISS
Sun, 31 May - Tue, 9 Jun
SWISS Logo
08:45 - 18:45
LHR
-
SAI
28h 00m
2 stops
SWISS Logo
09:40 - 21:45
SAI
-
LHR
18h 05m
2 stops
£597SWISS
Mon, 1 Jun - Mon, 8 Jun
Lufthansa Logo
07:25 - 18:45
LHR
-
SAI
29h 20m
2 stops
Lufthansa Logo
10:30 - 17:40
SAI
-
LHR
37h 10m
2 stops
£604Lufthansa
Mon, 1 Jun - Mon, 8 Jun
Lufthansa Logo
06:55 - 18:45
LHR
-
SAI
29h 50m
2 stops
Lufthansa Logo
10:30 - 17:40
SAI
-
LHR
37h 10m
2 stops
£605Lufthansa
Wed, 8 Apr - Wed, 3 Jun
Emirates Logo
14:55 - 21:30
STN
-
SAI
24h 35m
2 stops
Emirates Logo
12:55 - 12:55
SAI
-
STN
30h 00m
2 stops
£734Emirates
Wed, 29 Apr - Mon, 25 May
Emirates Logo
14:55 - 21:30
STN
-
SAI
24h 35m
2 stops
Emirates Logo
13:05 - 12:55
SAI
-
STN
29h 50m
2 stops
£736Emirates
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 April.

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 September, when tickets cost £693 (return) on average. On the other hand, the most expensive months are December and July, when the average cost of return tickets is £1,199 and £1,055 respectively.

How far in advance should I book a flight from London to Siem Reap?

To calculate weekly average prices, KAYAK takes all prices for each week before departure 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 average of all the values for each week.

To get a below-average price on a flight from London to Siem Reap, you should book around 2 weeks before departure, which saves you about 33% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 3 weeks before departure.

Good to know - Cheap tickets from London to Siem Reap

Low seasonJuly
Best time to beat the crowds but there is an average 22% increase in price.
Most popular time to fly and prices are also 6% 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 1479 reviews
8.3Boarding
8.0Entertainment
7.8Food
8.0Comfort
8.6Crew
Airline reviews

Crew is excellent Wifi needs to be improved in order to connect to the internet.

10.0 ExcellentTiep, Mar 2026
SIN - LAX
Read more Singapore Airlines reviews

Crew is excellent Wifi needs to be improved in order to connect to the internet.

Overall were very good and I was satisfied w/ all the food and services.

Food was served to different people at different times and it wasn't clear why. The crew apologized for the wait. But it felt odd and inconsistent. They could use charging ports on each of the seats. Mine didn't have any. Also, they could've offered more snacks. It was a 12+ hour flight and no snacks were ever offered. Everything else was OK.

No frills airline with minimal leg room and no entertainment

I wish there was a little more leg room between the seats. The recline was good and seats overall were comfortable. I also didn’t like the 2-4-2 configuration.

The crew was very courteous and professional. the flight is relatively clean and comfortable.

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

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

Food from Surabaya was below average but from Singapore is much better

The usual excellent experience with Singapore Airlines. The airplane was on time and actually early to Haneda Airport. The onboarding experience was pleasant with no delays, perhaps owing to the fact that the flight was not full. Nevertheless, the air crew were their usual outstanding standards in serving the passengers.

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.

Except that our flight was cancelled, by mail, and later moved to 12 hours prior, then the experience was good. In Bangkok we were offered a hotel, it was fine, but would have been nice to know in advance😉

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.

The flight crew and attendants are very professional and polite.

Food and welcome services were good , however we experienced issues with the entertainment system and poor headsets

Very good flight and very kind crew Only thing is I wish there would be a vegetarian option for the meals

the service on Business class should be improved to be at par with industry leaders like Cathay Pacific and Singapore AIrlines. A lot of room for improvement.

You will pay for everything and feels like the airplane is old

The luggage problem I previously mentioned was actually this flight

The flight was delayed due to snow in Frankfurt. There wasn't much information from BA or the airport, but Kayak was great and kept me informed of the delay and gate changes.

Late takeoff, but on time landing. Lost bags, 3 days to find them, still in transit to my location. Power outlets broken, Wi-Fi not working, so much for working on the long flight.

Good. For a long flight. The comfort of the seat could be better. Also, the food was « normal » plane food. Not indian plane food unfortunately! Everything else was smooth and great.

The seats were comfortable. So many empty seats allowed for stretching out and sleeping. The onboard entertainment was pretty good. The cabin crew were so kind and kept the passengers well- hydrated, and well fed.

We had American Airlines on our return and it was confusing if we were going with Aa or BA I had 2 different flight numbers and didn’t get our gate until it was boarding. So we were a bit nervous as the which it was

No WiFi. No food. 250 ml of water only drink option. No entertainment options. Extremely bare bones flight

Economy seats were good and spacious. Much better than virgin by a mile.

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.