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

Saturday is statistically the day of the week which experiences the fewest number of delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

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

Generally, flights departing in the morning tend to experience fewer delays. Flights at night have, in the past, seen delays more frequently in comparison.

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

According to our data, Delta have had the least number of delays on this route over the last 12 months; with about 11% of their flights experiencing any sort of delay.

How long does it take to fly to Ko Samui?

Flight times vary depending on what airport in Washington, D.C. you fly out of and what airport in Ko Samui you fly into. For example, flying from Baltimore to Ko Samui takes 30h 18m on average. On the other hand, flying from Washington, D.C. to Ko Samui takes 34h 48m on average. Keep in mind that it’s always quicker to opt for a non-stop flight, so be sure to check momondo if there are any available for your route.

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

Historically, on average around 19% of flights between Washington, D.C. and Ko Samui have experienced a delay on any given week. The average delay length over the past 12 months has been 130 minutes.

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

Prices for flights from Washington, D.C. to Ko Samui Airport are updated daily.

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

The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Washington, D.C. to Ko Samui Airport.

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

The required travel and health documents for your Ko Samui Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ko Samui Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$143 Cheap Flights from Washington, D.C. to Ko Samui in 2026

1 adult

0 bags

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

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

Trusted and free

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

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from Washington, D.C. to Ko Samui

Round-trip

One-way

Cheap round-trip flights

Enter your travel dates to find the best prices.

2:30 pm - 7:30 am

IAD

USM

30h 00m

2 stops

7:30 pm - 12:45 pm

USM

IAD

28h 15m

2 stops

$1,150Multiple Airlines

Thu, Mar 19 - Thu, Mar 26

10:15 pm - 6:15 pm

IAD

USM

33h 00m

2 stops

7:35 pm - 11:35 am

USM

IAD

27h 00m

2 stops

$1,230Multiple Airlines

Sat, Mar 21 - Sat, Mar 28

2:35 pm - 7:45 am

IAD

USM

29h 10m

2 stops

8:50 am - 10:05 am

USM

IAD

60h 15m

2 stops

$1,240Etihad Airways

Mon, Mar 2 - Mon, Mar 9

9:45 pm - 6:00 pm

IAD

USM

33h 15m

2 stops

7:55 pm - 11:35 am

USM

IAD

26h 40m

2 stops

$1,241Multiple Airlines

Wed, Apr 8 - Thu, Jun 4

9:45 pm - 2:45 pm

IAD

USM

30h 00m

2 stops

8:20 am - 11:35 am

USM

IAD

62h 15m

2 stops

$1,452Multiple Airlines

Sat, Apr 4 - Sat, Apr 11

9:45 pm - 6:15 pm

IAD

USM

33h 30m

2 stops

1:30 pm - 11:35 am

USM

IAD

57h 05m

2 stops

$1,455Multiple Airlines

Mon, Apr 6 - Sun, Apr 12

11:05 am - 10:30 am

IAD

USM

36h 25m

2 stops

5:55 pm - 8:45 am

USM

IAD

25h 50m

2 stops

$1,636Qatar Airways

Sun, Jul 26 - Fri, Jul 31

6:37 pm - 7:35 pm

DCA

USM

36h 58m

2 stops

11:40 am - 6:55 pm

USM

DCA

42h 15m

2 stops

$2,059Cathay Pacific

Mon, Mar 2 - Mon, Mar 9

9:30 pm - 6:15 pm

BWI

USM

57h 45m

2 stops

1:30 pm - 7:40 pm

USM

BWI

41h 10m

2 stops

$2,554British Airways

Mon, Apr 6 - Sun, Apr 12

9:35 pm - 6:15 pm

BWI

USM

57h 40m

2 stops

4:25 pm - 7:45 pm

USM

BWI

38h 20m

2 stops

$2,615British Airways

Thu, Mar 19 - Thu, Mar 26

Malaysia Airlines flights from Washington, D.C. to Ko Samui

Our best Malaysia Airlines deals on Washington, D.C. to Ko Samui flight tickets

Malaysia Airlines

Mar 19

IAD9:05 pmWashington, D.C. Dulles Intl

36h 45m

3 stops

USM8:50 pmKo Samui

Mar 26

USM8:30 amKo Samui

35h 50m

3 stops

IAD9:20 amWashington, D.C. Dulles Intl

$1,941

Malaysia Airlines

Jul 26

IAD9:00 pmWashington, D.C. Dulles Intl

32h 50m

3 stops

USM4:50 pmKo Samui

Jul 31

USM11:25 amKo Samui

32h 20m

3 stops

IAD8:45 amWashington, D.C. Dulles Intl

$3,172

Malaysia Airlines

Jul 6

IAD9:00 pmWashington, D.C. Dulles Intl

33h 05m

3 stops

USM5:05 pmKo Samui

Jul 13

USM9:15 amKo Samui

34h 30m

3 stops

IAD8:45 amWashington, D.C. Dulles Intl

$3,201

British Airways flights from Washington, D.C. to Ko Samui

Our best British Airways deals on Washington, D.C. to Ko Samui flight tickets

British Airways

Apr 6

BWI9:30 pmBaltimore/Washington

57h 45m

2 stops

USM6:15 pmKo Samui

Apr 12

USM1:30 pmKo Samui

41h 10m

2 stops

BWI7:40 pmBaltimore/Washington

$2,554

British Airways

Jul 6

BWI9:30 pmBaltimore/Washington

33h 45m

2 stops

USM6:15 pmKo Samui

Jul 13

USM4:25 pmKo Samui

38h 15m

2 stops

BWI7:40 pmBaltimore/Washington

$2,593

British Airways

Mar 19

BWI9:35 pmBaltimore/Washington

57h 40m

2 stops

USM6:15 pmKo Samui

Mar 26

USM4:25 pmKo Samui

38h 20m

2 stops

BWI7:45 pmBaltimore/Washington

$2,615

momondo Fare Finder

Use the filters below to find and compare flights from Washington, D.C. to Ko Samui that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Thu 3/19

2:30 pm-7:30 am

2 stops30h 00m

Ko Samui

Thu 3/26

7:30 pm-12:45 pm

2 stops28h 15m

$1,150

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Sat 3/21

10:15 pm-6:15 pm

2 stops33h 00m

Ko Samui

Sat 3/28

7:35 pm-11:35 am

2 stops27h 00m

$1,230

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Mon 3/2

2:35 pm-7:45 am

2 stops29h 10m

Ko Samui

Mon 3/9

8:50 am-10:05 am

2 stops60h 15m

$1,240

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Wed 4/8

9:45 pm-6:00 pm

2 stops33h 15m

Ko Samui

Thu 6/4

7:55 pm-11:35 am

2 stops26h 40m

$1,241

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Sat 4/4

9:45 pm-2:45 pm

2 stops30h 00m

Ko Samui

Sat 4/11

8:20 am-11:35 am

2 stops62h 15m

$1,452

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Mon 4/6

9:45 pm-6:15 pm

2 stops33h 30m

Ko Samui

Sun 4/12

1:30 pm-11:35 am

2 stops57h 05m

$1,455

Washington, D.C.Ko Samui

IAD - USM

IADUSM

Washington, D.C. Dulles Intl

Sun 7/26

11:05 am-10:30 am

2 stops36h 25m

Ko Samui

Fri 7/31

5:55 pm-8:45 am

2 stops25h 50m

$1,636

Washington, D.C.Ko Samui

DCA - USM

DCAUSM

Washington, D.C. Reagan-National

Mon 3/2

6:37 pm-7:35 pm

2 stops36h 58m

Ko Samui

Mon 3/9

11:40 am-6:55 pm

2 stops42h 15m

$2,059

BaltimoreKo Samui

BWI - USM

BWIUSM

Baltimore/Washington

Mon 4/6

9:30 pm-6:15 pm

2 stops57h 45m

Ko Samui

Sun 4/12

1:30 pm-7:40 pm

2 stops41h 10m

$2,554

BaltimoreKo Samui

BWI - USM

BWIUSM

Baltimore/Washington

Thu 3/19

9:35 pm-6:15 pm

2 stops57h 40m

Ko Samui

Thu 3/26

4:25 pm-7:45 pm

2 stops38h 20m

$2,615

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

How to get the cheapest flight ticket from Washington, D.C. 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

Prices

Delays

Other information

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. 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. 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. to Ko Samui

Are you open to changing your travel dates? Check out the ideal times to fly from Washington, D.C. 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. to Ko Samui (WAS to USM) flight deals and tips

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

Fastest flight time	29h 00m
Direct flights	None

The fastest flight from Washington, D.C. to Ko Samui takes 29h 00m

There are no direct flights from Washington, D.C. to Ko Samui. There are no popular flight routes from Washington, D.C. to Ko Samui.

Search flight deals

How far is Washington, D.C. to Ko Samui by plane?
Washington, D.C. and Ko Samui are 9079.2 mi apart from one another. A reasonable flight in good conditions will take 29h 00m.
When did momondo last update prices for flights from Washington, D.C. to Ko Samui Airport?
Prices for flights from Washington, D.C. to Ko Samui Airport are updated daily.
How old do you have to be to fly from Washington, D.C. to Ko Samui Airport?
The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Washington, D.C. to Ko Samui Airport.
What documentation or ID do you need to fly to Ko Samui Airport?
The required travel and health documents for your Ko Samui Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ko Samui Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular airline from Washington, D.C. to Ko Samui?
Based on momondo bookings for flights between Washington, D.C. and Ko Samui, the leading airline is Qatar Airways, making up 100% of the total bookings.

Ko Tao

Ko Pha Ngan

Khanom

Why use momondo?

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

It is quick and easy to find Washington, D.C. to Ko Samui flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Ko Samui that suits you.

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

All flight searches from Washington, D.C. to Ko Samui on momondo can be filtered to show those which offer flexible booking policies.

How can momondo help me find flights from Washington, D.C. to Ko Samui?

Once all potential Washington, D.C. to Ko Samui flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Yes. momondo can track prices for Washington, D.C. to Ko Samui flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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

Fri 3/6

Fri 3/13

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Thailand

Nearby airports

Cabin classes

Other Thailand destinations

Other flights from Washington, D.C.

Complete your trip

Feeling lucky

Cheap flights from Washington, D.C. to Ko Samui from $1,150

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. to Ko Samui departing on 3/19. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from Washington, D.C. to Ko Samui

Cheap round-trip flights

Cheap one-way flights

Malaysia Airlines flights from Washington, D.C. to Ko Samui

Our best Malaysia Airlines deals on Washington, D.C. to Ko Samui flight tickets

British Airways flights from Washington, D.C. to Ko Samui

Our best British Airways deals on Washington, D.C. to Ko Samui flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Washington, D.C. to Ko Samui that are best for you.

See travel insights to Ko Samui from

How to get the cheapest flight ticket from Washington, D.C. to Ko Samui

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

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

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

Historically, on average around 19% of flights between Washington, D.C. and Ko Samui have experienced a delay on any given week. The average delay length over the past 12 months has been 130 minutes.

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

Generally, flights departing in the morning tend to experience fewer delays. Flights at night have, in the past, seen delays more frequently in comparison.

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

Saturday is statistically the day of the week which experiences the fewest number of delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

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

According to our data, Delta have had the least number of delays on this route over the last 12 months; with about 11% of their flights experiencing any sort of delay.

How long does it take to fly to Ko Samui?

When to book flights from Washington, D.C. to Ko Samui

Cheap Washington, D.C. to Ko Samui (WAS to USM) flight deals and tips

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

Fastest flight time

Direct flights

How far is Washington, D.C. to Ko Samui by plane?

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

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

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

What is the most popular airline from Washington, D.C. to Ko Samui?

Traveling to a place near Ko Samui?

Why use momondo?

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

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

How can momondo help me find flights from Washington, D.C. to Ko Samui?

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

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.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to Thailand

Airports servicing Thailand

Cabin classes currently available on flights to Ko Samui

List of cabin classes available on flights landing in Ko Samui. Availability may vary depending on flight origin and airline.

Popular cities in Thailand

Popular flights according to clicks in the last 7 days on momondo

Fly to other destinations from Washington, D.C.

According to popular flight searches on momondo this year

Complete your trip to Ko Samui

Explore popular destinations other users love

According to popular flight searches on momondo this year