£321 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 10/2. 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, 4 Mar - Tue, 24 Mar
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
27h 30m
2 stops
China Eastern Logo
22:00 - 14:00
SAI
-
LGW
47h 00m
2 stops
£541China Eastern
Sun, 15 Mar - Sun, 22 Mar
Multiple Airlines Logo
17:00 - 21:00
LGW
-
SAI
45h 00m
3 stops
Multiple Airlines Logo
21:40 - 14:00
SAI
-
LGW
23h 20m
2 stops
£565Multiple Airlines
Sun, 15 Mar - Sun, 22 Mar
Multiple Airlines Logo
17:00 - 21:00
LGW
-
SAI
45h 00m
3 stops
Multiple Airlines Logo
21:40 - 14:00
SAI
-
LGW
23h 20m
2 stops
£567Multiple Airlines
Mon, 2 Mar - Sat, 28 Mar
China Eastern Logo
10:30 - 21:00
LGW
-
SAI
27h 30m
3 stops
China Eastern Logo
22:00 - 05:40
SAI
-
LGW
38h 40m
3 stops
£590China Eastern
Tue, 24 Feb - Tue, 24 Mar
Malaysia Airlines Logo
21:25 - 10:00
LHR
-
SAI
29h 35m
1 stop
Malaysia Airlines Logo
11:00 - 05:35
SAI
-
LHR
25h 35m
1 stop
£610Malaysia Airlines
Tue, 24 Feb - Tue, 24 Mar
Malaysia Airlines Logo
21:25 - 10:00
LHR
-
SAI
29h 35m
1 stop
Malaysia Airlines Logo
11:00 - 05:35
SAI
-
LHR
25h 35m
1 stop
£613Malaysia Airlines
Sun, 1 Mar - Tue, 24 Mar
SWISS Logo
19:20 - 09:50
LCY
-
SAI
31h 30m
2 stops
SWISS Logo
16:45 - 08:45
SAI
-
LCY
23h 00m
2 stops
£734SWISS
Wed, 25 Feb - Tue, 31 Mar
Emirates Logo
20:15 - 21:10
STN
-
SAI
17h 55m
2 stops
Emirates Logo
23:50 - 18:45
SAI
-
STN
24h 55m
2 stops
£764Emirates
Mon, 23 Feb - Tue, 17 Mar
Emirates Logo
20:15 - 21:10
STN
-
SAI
17h 55m
2 stops
Emirates Logo
23:50 - 12:05
SAI
-
STN
43h 15m
2 stops
£771Emirates
Mon, 23 Feb - Tue, 17 Mar
SWISS Logo
19:10 - 09:50
LCY
-
SAI
31h 40m
2 stops
SWISS Logo
16:45 - 08:45
SAI
-
LCY
23h 00m
2 stops
£776SWISS
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 March.

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 £668 (return) on average. On the other hand, the most expensive months are December and July, when the average cost of return tickets is £1,155 and £1,029 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 36% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 22 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 26% increase in price.
Most popular time to fly and prices are also 13% 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 1440 reviews
8.0Comfort
8.0Entertainment
8.3Boarding
8.6Crew
7.8Food
Airline reviews

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

10.0 ExcellentDulcie, Jan 2026
HKG - SIN
Read more Singapore Airlines reviews

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

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

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.

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 flight was mostly fine, but I really wished that seats had an outlet to charge devices considering the length of the flight (15 hours there and 14 hours back).

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

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

For a domestic flight, seats are ok, but fir us as tall dutchies, the legroom is too small. However, for a short and affordable flight, is not a big problem. Staff is still very nice and a complementary water very welcome.

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

Average, not more then that. Cannot compete with Singapore Airlines

I bought the front row seat and made and early online check in but they changed my seat to the back row without prior notice. The inflight meal was too poor, only a piece of small finger food. The boarding is a disaster, everyone is stuffed in a bus in chaos. Doesnt worth the money at all.

It’s the old style plane with the old Ying Yang seats doesn’t compare to other airlines with newer planes.

I was unable to board this flight because of visa changes that I was not alerted about and I’ve been unable to contact Kayak to obtain a refund / credit anything.

My touch screen at my seat wasn't working, the films BA advertised on the website for this flight were not available, and the plane was a little dated, food was good and the staff were good, just let down by the aircraft facilities.

Did not like the seating configuration at all with 2+3+2 in business class. Lacking total privacy and comfort

Check-in experience, for business call please provide a premium experience

Lost my luggage, ran out of food choices in business class, ground crew was completely unapologetic.

Excellent. The crew and flight were great. Checking in was easy and everyone was very helpful.

Late. And service was very slow - passengers sat for well over an hour with dirty trays etc surrounding them

Entertainment devices on A380 need to be fixed, the seats might do with updates.

I like everything about British Airways. Excellence. Perfect. Exquisite service.

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.