Find Cheap Flights from London to Siem Reap

1 adult
1 adult, Economy

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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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.

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 £710 (return) on average. On the other hand, the most expensive months are December and July, when the average cost of return tickets is £1,226 and £1,072 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 4 weeks before departure, which saves you about 30% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 5 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 24% increase in price.
Most popular time to fly and prices are also 15% 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.

  • What is the cheapest time of day to fly to Siem Reap?

    The cheapest time of day to fly to Siem Reap is generally at night, when retur flights cost £1,006 on average. Morning departures are around 9% cheaper than evening flights, on average. The most expensive time of day to fly to Siem Reap is generally in the evening, which is peak travel time and where the average cost of a ticket is £1,214.

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.
8.1
Singapore AirlinesOverall score based on 1338 reviews
7.9Comfort
8.2Boarding
8.6Crew
8.0Entertainment
7.7Food
Airline reviews

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

10.0 ExcellentAnonymous, Jul 2025SFO - SIN
Read more Singapore Airlines reviews

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.

Construction at PDX resulting in very lung walk from the rental car to the gate. SFO, extremely long walk between terminals to get to connecting Singapore airlines flight. My smart watch recorded a total of 3 miles.

The seat in economy class and legroom in Singapore airline are narrower than Korean airlines! I don’t have that comforting feeling flying with Singapore air as in the past!

I very much liked and appreciated the service on board. The seating arrangement in Business feels uncomfortable. It's not made for tall people, in any case.

Great airline. Excellent service, good food & lots of TV movies/shows to choose from.

Overall, very good. The food was better than expected with the exception of the pork and potatoes dinner at the end of the flight. My family all selected that dish and did not set it. I tried a bite also and it was honestly terrible. Also, it would be helpful to know when the snacks in the back of the plane are available.

Crews were very caring and polite. Washroom was surprisingly clean. Overall experience was good , only food choices was very limited. Thanks

On time boarding I would like to see ground hostess to help transit customers to direct them to the right terminal and boarding gate. Last night, all the transit customers on SQ484 arriving Singapore had to merry go round to look for terminal and boarding gate to board SQ128 transit to KL Malaysia. We went to Terminal 3 taking the Skytrain to T3 and back to T3 to get out to look for different Skytrain to T2. On arrival t2, we had to go round to ask which boarding gate to KL. We only had 5 minutes to make to the boarding time at 6:55pm but we already spent more than 30 minutes running around to find the boarding gate. We were late at the boarding gate.

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).

Although booked meal of fruit only The crew had not received this special meal The same happened on my flight Bangkok / CAN The films are so old that best is to use own computer to watch downloads . Serve nuts but they do not warm up . Service is attentive , WC clean

Terrible. It’s like they are stuck in the dark ages. I brought a standard carry on suitcase and a back pack - I was told I could only carry on 7kg per bag - in business class, I was forced to remove articles from the suitcase and put them into my backpack! That’s the most ridiculous thing I’ve ever encountered in all my years of flying. The two bags weighed the same amount but one could not be more than 7kg. Holy cow.

They used Thai Smile plane, which is a smaller model and used to service only domestic flights; hence, the plane is small and quite compact. No entertainment on the flight. While boarding was delayed, it was done in a quick manner.

I give EVA 5 stars in every category. I enjoy this airline and it's great team of employees. I always highly recommend EVA to friends and family and everyone.

The flight was delayed going out of the gate at BKK that made it a difficult challenge to get through immigration transfer at tapei and make it to my departure on time. This appears to be a recurring issue. The flight crew and cabin crew were excellent. The food was very nice.

The boarding efficiency was good. A couple of the flight attendants did not seem in the best of moods. Overall it was a good experience.

The setting configuration of the aircraft stinks. Nobody should pay business class fares and be so uncomfortable. The design of facing fellow passengers is a brilliant nincompoop.

Entertainment is limited with a relatively old catalogue. Wi-Fi never works and the cabin and lavatory had evidence of a lot of scuff marks and temporary repairs. Nothing unsafe, but a bit tatty in places.

Delayed flight in Singapore caused the transfer at Bangkok to be very stressful. Fortunately, no elderly were in this trip, else it will not be possible to catch the connecting flight. There were also several occasions throughout the flight journey where some of the passengers were not wearing their seat belts despite several remainders from the stewardess.

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.

Poor. Flight was delay without prior notice. Poor boarding. Poor meal service. Plane was dirty and smelly. Does not worth the money.

Overall very nice airline. The seats were cloth unlike leather seats I am accustom to on planes. The food was adequate. I had to use a paper boarding pass as they do not like electronic boarding passes. I scanned my electronic pass, but the gate agent requested the paper pass. Luckily I had a paper pass, although my electronic pass worked and when the paper pass was scanned it stated I was already on board.

I am a bit upset with the check in counter, I signed up a wheelchair for my mom so they wouldn’t grant us her boarding pass. We got to the airport a couple of hours earlier and they had us wait and no one ever gave us her boarding pass or the wheelchair, I had to go back and complain when it was already time for our flight to board. Since we got their earlier, I could have easily pushed my mom myself and we could have relaxed and went to the lounge while waiting… when I finally got someone to help us he couldn’t explain how and why they dismissed us in the first place.

Was on holiday with my partner and we booked with Vietnam airlines as it not meant to be a budget airline. They separated us and made us sit at either end of the plane. Not the way I planned to spend my time on my holiday separate from my loved one. How can they separate people on the same booking. They know we are together and spending quality time together.

I had sometimes my trips with Vietnam Airlines and I like it 😊

The check-in process was great, and I cannot remember the name of the supervisor, but he was good and told us about the transit process very correctly and efficiently and kindly. We were given down access and the overall process was very efficient.

The plane had a technical problem it would delayed 10 hours but they just gave limited information and put all passengers into the Miracle lounge. Ther were not enough chairs and so on.

Everything about the flight check-in was smooth no line the plane is clean and bathroom

Excellent everywhere but Philly, the most rotten airport in the world.

Check in was not the greatest as had to talk to an agent to clarify things and then he transferred us to another agent who had difficulty processing my credit card as there was a system glitch and not a card error.

All good. Loo’s weren’t great and as clean as i would like.

A great flight. The crew was excellent too. Of particular note of excellence was the gluten-free meal which was one of the best offerings I’ve ever had on a plane. Outstanding work, BA chefs.

I was put into business class. Wow! My flight attendant was great! The food amazing’

The gate at London Gatwick had confusing signs for the different zones and the staff seemed harried because people didn't know when it was their turn to come to the desk. Plus, with there were too many carry-on bag travelers, myself included. The charge scheme for checking bags is frustrating. If you travel light, you want the freedom to leave as soon as you deplane. When you are forced to gate-check your bag simply because the flight is fully booked, you lose whatever time you'd hoped to save because you're still stuck waiting for your bag to come off the conveyor belt.

I got stuffed on both flights into terrible seats. Second flight the seat didn’t even recline and fit s tall person, that’s very uncomfortable.

I arrived at Bridgetown only to fins that a suitcase was missing. It was left at Manchester. I had to wait wait 2 days before deciding on going to collect from the airport personally. I am not happy about paying for baggage at the airport. This I thought was included in the price of the ticket. Who goes away for 2 weeks and does not bring luggage. This was a total rip off and I am not happy. I need someone to contact me before returning so that I don't have to pay all over again to return homde.

Boarding market okay just because of the delay we had, but not related to the crew in any way…

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.

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