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Ko Samui

$1,093+ Cheap flights from Washington, D.C. (WAS) to Ko Samui (USM)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/4. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — USM
Jan 14 — Jan 211
Wed 1/14
Wed 1/21
1 adult, Economy
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Cheap flight deals from Washington, D.C. to Ko Samui

Cheapest flights from Washington, D.C. to Ko Samui
Explore the most affordable flight options available from Washington, D.C. to Ko Samui. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 15, 2025.

This Gotogate deal was found by Cheapflights users on 12/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/218:05 pmIAD - USM
2 stops24h 20mMultiple Airlines
Wed 12/241:25 pmUSM - IAD
2 stops38h 30mMultiple Airlines
Deal found 12/13$2,758
This oojo deal was found by Cheapflights users on 12/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/216:35 pmDCA - USM
2 stops37h 00mCathay Pacific
Wed 12/241:45 pmUSM - DCA
3 stops39h 28mCathay Pacific
Deal found 12/13$4,142
This oojo deal was found by Cheapflights users on 12/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/217:11 pmBWI - USM
2 stops36h 24mCathay Pacific
Wed 12/248:30 amUSM - BWI
3 stops26h 28mCathay Pacific
Deal found 12/13$6,766
This Gotogate deal was found by Cheapflights users on 12/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/218:35 pmBWI - USM
2 stops33h 40mBritish Airways
Wed 12/244:25 pmUSM - BWI
2 stops38h 20mBritish Airways
Deal found 12/13$9,498

Find flight deals from Washington, D.C. to Ko Samui

Discover tips and strategies to find the most affordable flight options for your journey from Washington, D.C. (WAS) to Ko Samui (USM). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated December 15, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$1,093
(oojo)
Provider with most accurate pricing for Washington, D.C. (WAS)-Ko Samui flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. (WAS)-Ko Samui flights.
Search Deals
From Washington, D.C. (WAS) to Ko Samui
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Washington, D.C. 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, Cheapflights users made 2,558,603 searches. Data last updated December 15, 2025.
Use the filters below to find and compare flights from Washington, D.C. to Ko Samui that are best for you.

Fly from

Washington, D.C.

Fly to

Ko Samui

Route

Depart

Return

Price

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Wed 3/4

2:35 pm-7:45 am

2 stops29h 10m

Ko Samui

Wed 3/11

8:50 am-10:05 am

2 stops60h 15m

$1,093

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Tue 1/27

2:35 pm-7:45 am

2 stops29h 10m

Ko Samui

Tue 2/3

8:15 am-9:05 am

2 stops36h 50m

$1,227

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Wed 3/4

9:59 am-7:35 pm

2 stops45h 36m

Ko Samui

Wed 3/11

11:40 am-8:01 am

2 stops31h 21m

$1,498

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Wed 3/4

2:35 pm-8:05 am

2 stops29h 30m

Ko Samui

Wed 3/11

12:00 pm-10:05 am

3 stops33h 05m

$1,502

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Tue 1/27

2:35 pm-8:05 am

2 stops29h 30m

Ko Samui

Tue 2/3

8:30 pm-8:29 pm

3 stops35h 59m

$1,553

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Thu 1/8

2:35 pm-7:35 pm

2 stops41h 00m

Ko Samui

Wed 1/14

8:50 am-9:05 am

2 stops60h 15m

$1,675

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Tue 1/27

6:42 pm-7:35 pm

2 stops36h 53m

Ko Samui

Tue 2/3

11:40 am-6:44 pm

2 stops43h 04m

$1,732

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Sun 5/31

11:00 am-7:10 am

3 stops33h 10m

Ko Samui

Mon 6/15

7:55 pm-7:58 pm

3 stops35h 03m

$1,852

BaltimoreKo Samui

BWI - USM

BWIUSM

Baltimore/Washington

Wed 1/14

8:00 am-6:15 pm

3 stops46h 15m

Ko Samui

Wed 1/21

1:25 pm-9:26 pm

2 stops44h 01m

$1,948

BaltimoreKo Samui

BWI - USM

BWIUSM

Baltimore/Washington

Wed 4/8

6:18 pm-9:10 pm

2 stops39h 52m

Ko Samui

Sun 4/19

1:30 pm-5:07 pm

2 stops38h 37m

$2,005

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/13

Showing 1-10 of 33 results
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Compare providers for flights from Washington, D.C. to Ko Samui

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Washington, D.C. to Ko Samui in December.
ProviderPrice AccuracyTrust Score*
OvagoPrice Accuracy2 starsTrust Score*2 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy2 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C.-Ko Samui flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Washington, D.C.-Ko Samui flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Washington, D.C.-Ko Samui flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C.-Ko Samui flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C.-Ko Samui flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Washington, D.C. to Ko Samui

Have a flexible travel schedule? Discover the best time to fly to Ko Samui from Washington, D.C. with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington, D.C. to Ko Samui

What is the cheapest time of day to fly from WAS to USM?

Find hourly flight availability from Washington, D.C. to Ko Samui. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 15, 2025.

One of the essential ways to save on airfare from Washington, D.C. to Ko Samui is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the evening could potentially save you up to 37% on airfare.

What is the cheapest day to fly from Washington, D.C. to Ko Samui?

Use this chart to determine the cheapest time to fly round-trip from Washington, D.C. to Ko Samui. Price data was last updated on March 30, 2025.

Travelers seeking maximum savings on their Washington, D.C. to Ko Samui flight should consider departing on Monday at noon when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

How often are flights from Washington, D.C. to Ko Samui delayed?

About 17% of weekly flights between Washington, D.C. and Ko Samui have experienced delays in the past year, with the average delay time being 133 minutes.

What is the most punctual flight time for Washington, D.C. to Ko Samui flights?

Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.

What day of the week experiences the fewest flight delays on this route?

Saturday tends to have the lowest number of delays on this route, whereas Monday has historically faced a higher average of delays compared to other days of the week.

Which airline has the best punctuality record on Washington, D.C. to Ko Samui flights?

Over the last year, United Airlines have had the lowest number of delays on this route, with just 10% of flights being delayed.

Reviews of airlines servicing Ko Samui

Get insights into the airlines that provide service to Ko Samui. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ko Samui. Reviews last updated December 15, 2025.
Peruse reviews from past customers who have flown with Qatar Airways from Washington, D.C. to Ko Samui to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Qatar Airways
7.4
Good
3,681 reviews

Comfort

7.4

Crew

7.9

Boarding

7.5

Food

7.3

Overall

7.4

Entertainment

7.4

Reviews

1 / 20
6.0
Good

Chris,Jul 2025

DFW - DOH

Too crammed for the amount you have to pay. That was very uncomfortable
Qatar Airways
7.4
Good
3,681 reviews
Qatar Airways
7.4
Good
3,681 reviews

Comfort

7.4

Crew

7.9

Boarding

7.5

Food

7.3

Overall

7.4

Entertainment

7.4

Reviews

1 / 20
6.0
Good

Chris,Jul 2025

DFW - DOH

Too crammed for the amount you have to pay. That was very uncomfortable

Related info for your journey

Find useful and relevant information for your journey from Washington, D.C. to Ko Samui. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Ko Samui from Washington, D.C.?

    For a flight from Washington, D.C. to Ko Samui, you will be flying into Ko Samui. Ko Samui (USM) is just 2.1 mi from the center of the city. Ko Samui is the only Ko Samui airport and it handles 0 inbound flights from Washington, D.C. per day. 0 airlines have flights to Ko Samui from Washington, D.C. on a regular basis.

  • How long is the flight from Washington, D.C. to Ko Samui?

    Etihad Airways, Cathay Pacific, and Singapore Airlines can get you from Washington, D.C. to Ko Samui in just under 29h 10m. Your travel time can differ by up to 17h 05m. There are 9076 mi between Washington, D.C. and Ko Samui. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the most popular routes from Washington, D.C. to Ko Samui?

    The most popular flight routes from Washington, D.C. to Ko Samui are Washington, D.C. Reagan-National - Ko Samui, Washington, D.C. Dulles Intl - Ko Samui and Baltimore/Washington - Ko Samui.

  • Can I find deals for flights from Washington, D.C. to Ko Samui that include hotel bookings?

    Yes. In addition to deals on Washington, D.C. to Ko Samui flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Washington, D.C. to Ko Samui?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Washington, D.C. to Ko Samui.

  • Can I find deals for business class flights from Washington, D.C. to Ko Samui?

    Yes. Cheapflights offers flight deals from Washington, D.C. to Ko Samui by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

Traveling to a place near Ko Samui?

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

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