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Cheap flights from Washington, D.C. Reagan-National Airport to Ko Samui from $1,636

This is the cheapest round-trip 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 10/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Washington, D.C. Reagan-National Airport to Ko Samui

Cheap round-trip flights

Cathay Pacific Logo
12:31 pm - 6:35 pmDCA-USM
43h 04m2 stops
Cathay Pacific Logo
10:55 am - 8:16 pmUSM-DCA
44h 21m2 stops
$1,636Cathay Pacific
Find Deal
Wed, Oct 15 - Wed, Oct 22
Cathay Pacific Logo
12:31 pm - 6:35 pmDCA-USM
43h 04m2 stops
Cathay Pacific Logo
2:35 pm - 8:16 pmUSM-DCA
40h 41m3 stops
$1,828Cathay Pacific
Find Deal
Wed, Oct 15 - Wed, Oct 22
Multiple Airlines Logo
6:38 am - 8:15 amDCA-USM
38h 37m3 stops
Multiple Airlines Logo
9:00 pm - 9:51 pmUSM-DCA
35h 51m3 stops
$1,945Multiple Airlines
Find Deal
Wed, Oct 15 - Wed, Oct 22
Multiple Airlines Logo
8:40 pm - 6:35 pmDCA-USM
34h 55m2 stops
Multiple Airlines Logo
11:40 am - 8:55 amUSM-DCA
32h 15m2 stops
$7,294Multiple Airlines
Find Deal
Sun, Oct 19 - Sun, Oct 26

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
Oct 15
DCA12:31 pmWashington, D.C. Reagan-National
43h 04m
2 stops
USM6:35 pmKo Samui
Oct 22
USM10:55 amKo Samui
44h 21m
2 stops
DCA8:16 pmWashington, D.C. Reagan-National
$1,636
Find similar
Cathay Pacific
Oct 15
DCA12:31 pmWashington, D.C. Reagan-National
43h 04m
2 stops
USM6:35 pmKo Samui
Oct 22
USM2:35 pmKo Samui
40h 41m
3 stops
DCA8:16 pmWashington, D.C. Reagan-National
$1,828
Find similar

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 September 21, 2025.
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

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Wed 10/15

12:31 pm-6:35 pm

2 stops43h 04m

Ko Samui

Wed 10/22

10:55 am-8:16 pm

2 stops44h 21m

$1,636

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Wed 10/15

12:31 pm-6:35 pm

2 stops43h 04m

Ko Samui

Wed 10/22

2:35 pm-8:16 pm

3 stops40h 41m

$1,828

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Wed 10/15

6:38 am-8:15 am

3 stops38h 37m

Ko Samui

Wed 10/22

9:00 pm-9:51 pm

3 stops35h 51m

$1,945

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Sun 10/19

8:40 pm-6:35 pm

2 stops34h 55m

Ko Samui

Sun 10/26

11:40 am-8:55 am

2 stops32h 15m

$7,294

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Tue 10/7

12:31 pm-2:45 pm

3 stops39h 14m

$4,004

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Tue 10/7

7:02 pm-6:35 pm

2 stops36h 33m

$4,370

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Mon 10/6

12:31 pm-2:45 pm

3 stops39h 14m

$4,389

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Tue 10/7

7:02 pm-6:35 pm

2 stops36h 33m

$4,527

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Mon 10/6

12:31 pm-6:35 pm

2 stops43h 04m

$4,615

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Mon 10/6

6:59 pm-6:35 pm

2 stops36h 36m

$5,081

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 13 resultsSorted by cheapest first
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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 day to depart on your flight to Ko Samui?

Our data shows that Wednesday is the least expensive day to fly to Ko Samui. Tickets to fly out on this day can be as low as $325. Flights from Washington, D.C. Reagan-National Airport to Ko Samui on a Sunday will generally be more expensive and average around $714. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

What is the cheapest time of day to depart on your flight to Ko Samui?

Our data shows that the cheapest Washington, D.C. Reagan-National Airport to Ko Samui flights are usually those with departure times in the evening. Our users have found flights to Ko Samui in the evening for as low as $286. At noon is when there is more demand to fly to Ko Samui, so prices are often more expensive at around $399 per ticket.

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

Direct flights

None
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.
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  • 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. 34h 55m 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.

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