Latest deals
Insights
When to book
FAQs
Price Alerts

Cheap flights from Washington, D.C. Reagan-National Airport to Ko Samui from $941

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington, D.C. Reagan-National Airport to Ko Samui departing on 7/9. 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 Washington, D.C. Reagan-National Airport to Ko Samui

Cheap round-trip flights

Enter your travel dates to find the best prices.
Cathay Pacific Logo
6:59 pm - 7:40 pm
DCA
-
USM
37h 41m
2 stops
Cathay Pacific Logo
11:55 am - 11:58 pm
USM
-
DCA
47h 03m
2 stops
$1,762Cathay Pacific
Tue, Sep 1 - Mon, Sep 7
Cathay Pacific Logo
7:35 am - 7:40 pm
DCA
-
USM
49h 05m
2 stops
Cathay Pacific Logo
11:55 am - 5:59 pm
USM
-
DCA
41h 04m
2 stops
$1,867Cathay Pacific
Thu, Aug 20 - Mon, Aug 31
Multiple Airlines Logo
9:30 am - 6:15 pm
DCA
-
USM
44h 45m
2 stops
Multiple Airlines Logo
1:25 pm - 8:00 pm
USM
-
DCA
42h 35m
2 stops
$2,400Multiple Airlines
Mon, Nov 16 - Mon, Nov 23

Cathay Pacific flights from Washington, D.C. Reagan-National Airport to Ko Samui

Our best Cathay Pacific deals on Washington, D.C. Reagan-National Airport to Ko Samui flight tickets
Cathay Pacific
Sep 1
DCA6:59 pmWashington, D.C. Reagan-National
37h 41m
2 stops
USM7:40 pmKo Samui
Sep 7
USM11:55 amKo Samui
47h 03m
2 stops
DCA11:58 pmWashington, D.C. Reagan-National
$1,762
Cathay Pacific
Aug 20
DCA7:35 amWashington, D.C. Reagan-National
49h 05m
2 stops
USM7:40 pmKo Samui
Aug 31
USM11:55 amKo Samui
41h 04m
2 stops
DCA5:59 pmWashington, D.C. Reagan-National
$1,867

momondo Fare Finder

 
Customize your flight search to find flights from Washington, D.C. Reagan-National Airport to Ko Samui 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 4, 2026.
Use the filters below to find and compare flights from Washington, D.C. Reagan-National Airport to Ko Samui that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Tue 9/1

6:59 pm-7:40 pm

2 stops37h 41m

Ko Samui

Mon 9/7

11:55 am-11:58 pm

2 stops47h 03m

$1,762

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Thu 8/20

7:35 am-7:40 pm

2 stops49h 05m

Ko Samui

Mon 8/31

11:55 am-5:59 pm

2 stops41h 04m

$1,867

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Mon 11/16

9:30 am-6:15 pm

2 stops44h 45m

Ko Samui

Mon 11/23

1:25 pm-8:00 pm

2 stops42h 35m

$2,400
Cheapest one-way

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Thu 7/9

9:59 am-7:30 am

3 stops58h 31m

$941
Quickest one-way

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Thu 7/9

6:55 pm-7:40 pm

2 stops37h 45m

$1,386

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to Ko Samui from

How to get the cheapest flight ticket from Washington, D.C. Reagan-National Airport to Ko Samui

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest airline that flies from Washington, D.C. Reagan-National to Ko Samui?

Cathay Pacific is the most popular carrier operating from Washington, D.C. Reagan-National to Ko Samui

When to book flights from Washington, D.C. Reagan-National Airport to Ko Samui

Are you open to changing your travel dates? Check out the ideal times to fly from Washington, D.C. Reagan-National Airport to Ko Samui according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Washington, D.C. Reagan-National Airport to Ko Samui (DCA to USM) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Washington, D.C. Reagan-National Airport to Ko Samui

Fastest flight time

37h 41m

Direct flights

None
The fastest flight from Washington, D.C. Reagan-National Airport to Ko Samui takes 37h 41m
There are no direct flights from Washington, D.C. Reagan-National Airport to Ko Samui. There are no popular flight routes from Washington, D.C. Reagan-National Airport to Ko Samui.
Search flight deals

Frequently asked questions about flying from Washington, D.C. Reagan-National Airport to Ko Samui

  • How far is Washington, D.C. Reagan-National to Ko Samui by plane?

    There are 9082.9 mi between Washington, D.C. Reagan-National and Ko Samui. 37h 41m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Washington, D.C. Reagan-National Airport to Ko Samui Airport?

    Prices for flights from Washington, D.C. Reagan-National Airport to Ko Samui Airport were last updated today.

  • How old do you have to be to fly from Washington, D.C. Reagan-National Airport to Ko Samui Airport?

    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 Washington, D.C. Reagan-National Airport to Ko Samui Airport.

  • What documentation or ID do you need to fly to Ko Samui Airport?

    The travel and health documents required for your trip to Ko Samui Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Ko Samui Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

Traveling to a place near Ko Samui?

Book flights to Ko Samui if you plan to visit one of these locations
Ko Pha Ngan
Ko Tao
Khanom

Why use momondo?

Why should I use momondo to find a flight deal from Washington, D.C. to Ko Samui?

Finding the right flight to Ko Samui from Washington, D.C. is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Ko Samui quick and easy, saving you time and money.

Can I find flights from Washington, D.C. to Ko Samui with flexible booking policies on momondo?

Flights from Washington, D.C. to Ko Samui 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 Washington, D.C. to Ko Samui?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Ko Samui from Washington, D.C..

I’m not ready to book a flight from Washington, D.C. to Ko Samui right now. Can momondo alert me if prices change?

Price alerts on flights to Ko Samui from Washington, D.C. are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your Ko Samui 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
Sat 7/4
Sat 7/11
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Thailand