The cheapest times to fly from ORD to REP are

  • January 1st to March 25th
  • August 27th to December 9th (except the week of October 15th)

based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from ORD to REP is late February and early March. Prices can be as high as $3993 for Saturday flights during late June, or as low as $1011 for Sunday flights around late February and early March.


When to Fly to Krong Siem Reap

Flying from Chicago, IL (ORD) to Siem Reap (REP) will usually cost between $1092 to $3328 per person if booking more than four weeks in advance. On average the very cheapest time to fly is late February and early March with an average ticket price of $1252. Due to high demand the most expensive time to fly is late June, with an average price of $2948. Planning your trip to low-cost times can easily save you $1696 on economy flights and even more on first-class flights. Generally, any price below $1716 can be considered a good price for a round-trip ORD to REP flight.

See below for a graph of average weekly prices for the ORD to REP route. All prices are for round-trip tickets in USD.

ORD to REP Flight Prices

Compared to other flights, the ORD to REP flight is more expensive than the average and costs more than the average flight leaving from Chicago. The average price per mile (for a direct flight) is $0.12, which is far below average.


Flight Prices by Day of the Week

Sunday is usually the cheapest day to depart and return on this flight. Saturdays are the most expensive days to fly to Krong Siem Reap, and Tuesdays are the most expensive days to return to Chicago. Selecting flights on the least expensive days could save you up to $655 (30%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Sunday and returning a week later will cost an average of $1566. Return trip prices are from the REP to ORD flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from ORD to REP can generally find a 1-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 16 hour 21 minutes may not be realistic.


Alternative Nearby Airports

Champion Traveler tells you which airports are nearby and whether tickets might be cheaper alternative airports nearby. Sometimes it’s worth it to fly into a closer airport and then commute to your destination. Remember that there is not usually a nonstop flight from ORD to REP while comparing.

Destination alternative #1: Phnom Penh International Airport (PNH) in Phnom Penh

  • 146 miles (235 km) away from REP
  • Usually 42.93% less expensive than REP
  • 1-layover flights available

See ORD to PNH flights


Flight Hacking ORD to REP

Flight hacking is when you book two tickets instead of a layover, sometimes with different airlines. You will need to either bring only a carry-on bag (highly recommended) or leave yourself plenty of time to go through security again. Flight hacking is completely allowed, but airlines don’t always tell you the cheapest way to get from ORD to REP — but Champion Traveler does!

Hack #1: Kuala Lumpur (ORD > KUL > REP)

  • Price for both tickets: $899
  • Average savings: $817 (47.6%)

See ORD to KUL flights

Hack #2: Bangkok (ORD > BKK > REP)

  • Price for both tickets: $922
  • Average savings: $794 (46.25%)

See ORD to BKK flights

Hack #3: Beijing (ORD > PEK > REP)

  • Price for both tickets: $994
  • Average savings: $722 (42.09%)

See ORD to PEK flights


Flight Questions Answered

Still have questions about flying from ORD to REP? We’ve got answers.

Which airlines fly this route?

You can find 26 major airlines flying this route most often: Air Canada, Air France, American, ANA, Asiana, Austrian, Bangkok Airways, British Airways, Cathay Pacific, China Eastern, China Southern, Delta, Emirates, Etihad, EVA Air, Finnair, JAL, KLM, Lufthansa, Qatar Airways, SAS, Singapore Airlines, THAI, Turkish Airlines, United, Vietnam Airlines, and potentially more during busy seasons.

How far away is it from Siem Reap International Airport to Chicago O’Hare International Airport?

The distance between the two airports is roughly 8536 miles or 13737 kilometers.

How long does it take to fly from ORD to REP?

The real-world flight time for a nonstop ORD to REP flight is about 16 hour 21 minutes.

How many flights go between Chicago, IL and Siem Reap?

It depends on the day of the week and the date, but a typical day might have around 12 available flights from ORD to REP.


Airport Location Info


Departing Airport

Origination code ORD
Origination airport name Chicago O’Hare International Airport
City Chicago, IL
Country the United States
Latitude 42
Longitude -87.9

Return Airport

Destination code REP
Destination airport name Siem Reap International Airport
City Siem Reap
Country Cambodia
Latitude 13.4
Longitude 103.8


Other Resources

Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.