Latest deals
FAQs
Price Alerts

Cheap flights from St. Louis to Siem Reap from $1,517

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Siem Reap departing on 10/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from St. Louis to Siem Reap

Cheap round-trip flights

Enter your travel dates to find the best prices.
ANA Logo
9:04 am - 5:10 pm
STL
-
SAI
44h 06m
3 stops
ANA Logo
7:10 pm - 2:07 pm
SAI
-
STL
30h 57m
3 stops
$1,517ANA
Wed, Oct 7 - Wed, Oct 14
Multiple Airlines Logo
4:40 pm - 9:40 am
STL
-
SAI
53h 00m
2 stops
Multiple Airlines Logo
10:30 am - 11:59 pm
SAI
-
STL
49h 29m
2 stops
$1,558Multiple Airlines
Wed, Oct 7 - Wed, Oct 14
Multiple Airlines Logo
9:47 am - 9:00 am
STL
-
SAI
35h 13m
3 stops
Multiple Airlines Logo
4:00 pm - 11:59 pm
SAI
-
STL
43h 59m
2 stops
$2,216Multiple Airlines
Wed, Oct 7 - Wed, Oct 14

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Region of Siem Reap that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated June 7, 2026.
Use the filters below to find and compare flights from St. Louis to Siem Reap that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

St. LouisSiem Reap

STL - SAI

STLSAI

Lambert-St Louis

Wed 10/7

9:04 am-5:10 pm

3 stops44h 06m

Siem Reap–Angkor Intl

Wed 10/14

7:10 pm-2:07 pm

3 stops30h 57m

$1,517

St. LouisSiem Reap

STL - SAI

STLSAI

Lambert-St Louis

Wed 10/7

4:40 pm-9:40 am

2 stops53h 00m

Siem Reap–Angkor Intl

Wed 10/14

10:30 am-11:59 pm

2 stops49h 29m

$1,558

St. LouisSiem Reap

STL - SAI

STLSAI

Lambert-St Louis

Wed 10/7

9:47 am-9:00 am

3 stops35h 13m

Siem Reap–Angkor Intl

Wed 10/14

4:00 pm-11:59 pm

2 stops43h 59m

$2,216

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

Cheap St. Louis to Region of Siem Reap flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Region of Siem Reap

Fastest flight time

44h 06m

Direct flights

None
The fastest flight from St. Louis to Region of Siem Reap takes 44h 06m
There are no direct flights from St. Louis to Region of Siem Reap. There are no popular flight routes from St. Louis to Region of Siem Reap.
Search flight deals

Frequently asked questions about flying from St. Louis to Siem Reap

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Siem Reap?

    Prices for flights from Lambert-St Louis Airport to Siem Reap are refreshed on a daily basis.

  • How old do you have to be to fly from Lambert-St Louis Airport to Siem Reap?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Siem Reap.

  • What documentation or ID do you need to fly to Siem Reap?

    The travel and health documents you'll need for your trip to Siem Reap may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Siem Reap. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Frequently asked questions about flying from St. Louis to Siem Reap

  • How do I get Price Alerts for flights from St. Louis to Region of Siem Reap?

    Search flight deals from St. Louis to Region of Siem Reap. While viewing offers you’ll have the option to create a Price Alert.

  • How can I save money on flights from St. Louis to Region of Siem Reap with momondo?

    With “Price Forecast”, learn how soon you should book your flight in advance. Down to the day of week and time of day, our information can inform you on the ideal time to book to save on your travel. Our “Price Calendar” shows you at a quick glance when to book your travel for lower rates. By setting “Price Alerts” you can monitor changes in price and target the ideal time to book. Search for your trip destination by budget amount via our “Explore” feature. Whether you’re looking for ideas for your next travel adventure or cost-cutting tips, our “Discover” content is a great place to start.

  • How does momondo find its flight prices?

    We aggregate our prices from over 700+ competitors from airlines to OTAs. We operate in over 30 markets worldwide to show you a wide range of travel options.

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Siem Reap?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from St. Louis to Siem Reap for you.

Can I find flights from St. Louis to Siem Reap with flexible booking policies on momondo?

Flights from St. Louis to Siem Reap with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from St. Louis to Siem Reap?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Siem Reap.

I’m not ready to book a flight from St. Louis to Siem Reap right now. Can momondo alert me if prices change?

If you are not ready to book a flight from St. Louis to Siem Reap now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Siem Reap and let you know when they change.

An easier way to manage your Region of Siem Reap trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Tue 7/7
Tue 7/14
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Siem Reap

Popular cities in Siem Reap

Popular flights according to clicks in the last 7 days on momondo
Flights to Phnom Penhfrom $1,020
Flights to Siem Reapfrom $753
Flights to Krong Preah Sihanoukfrom $1,253