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Cheap flights from Washington to Ko Samui from $643

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 to Ko Samui departing on 6/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Washington to Ko Samui

Cheap round-trip flights

Enter your travel dates to find the best prices.
Singapore Airlines Logo
10:15 am - 7:45 am
SEA
-
USM
31h 30m
1 stop
Singapore Airlines Logo
7:45 pm - 8:45 am
USM
-
SEA
51h 00m
1 stop
$972Singapore Airlines
Sat, Jun 13 - Tue, Jun 30
EVA Air Logo
11:50 pm - 4:25 pm
SEA
-
USM
26h 35m
2 stops
EVA Air Logo
9:20 am - 6:30 pm
USM
-
SEA
23h 10m
2 stops
$975EVA Air
Thu, Mar 19 - Thu, Mar 26
Multiple Airlines Logo
1:15 am - 8:50 pm
SEA
-
USM
29h 35m
2 stops
Multiple Airlines Logo
8:10 am - 4:10 pm
USM
-
SEA
22h 00m
2 stops
$1,006Multiple Airlines
Thu, Apr 9 - Sun, Apr 19
Singapore Airlines Logo
9:45 am - 5:10 pm
SEA
-
USM
41h 25m
1 stop
Singapore Airlines Logo
8:55 am - 8:10 am
USM
-
SEA
37h 15m
1 stop
$1,018Singapore Airlines
Thu, Mar 19 - Thu, Mar 26
Multiple Airlines Logo
11:45 pm - 9:20 pm
SEA
-
USM
30h 35m
2 stops
Multiple Airlines Logo
8:15 am - 3:05 pm
USM
-
SEA
21h 50m
2 stops
$1,143Multiple Airlines
Sun, Feb 15 - Tue, Feb 24
Multiple Airlines Logo
11:45 pm - 9:20 pm
SEA
-
USM
30h 35m
2 stops
Multiple Airlines Logo
8:15 am - 3:05 pm
USM
-
SEA
21h 50m
2 stops
$1,162Multiple Airlines
Sun, Feb 15 - Tue, Feb 24
Multiple Airlines Logo
11:45 pm - 9:20 pm
SEA
-
USM
30h 35m
2 stops
Multiple Airlines Logo
8:15 am - 3:05 pm
USM
-
SEA
21h 50m
2 stops
$1,183Multiple Airlines
Sun, Feb 15 - Tue, Feb 24
Multiple Airlines Logo
7:05 pm - 8:15 am
PDX
-
USM
23h 10m
2 stops
Multiple Airlines Logo
4:25 pm - 2:40 pm
USM
-
PDX
36h 15m
2 stops
$1,209Multiple Airlines
Sat, Apr 18 - Wed, Apr 22
Multiple Airlines Logo
11:45 am - 11:15 am
SEA
-
USM
33h 30m
2 stops
Multiple Airlines Logo
9:00 pm - 10:05 am
USM
-
SEA
27h 05m
2 stops
$1,228Multiple Airlines
Sat, Apr 4 - Sun, Apr 19
Multiple Airlines Logo
3:42 pm - 1:45 pm
PDX
-
USM
32h 03m
3 stops
Multiple Airlines Logo
2:00 pm - 10:53 pm
USM
-
PDX
22h 53m
3 stops
$1,232Multiple Airlines
Sat, Apr 18 - Wed, Apr 22

Singapore Airlines flights from State of Washington to Ko Samui

Our best Singapore Airlines deals on State of Washington to Ko Samui flight tickets
Singapore Airlines
Jun 13
SEA10:15 amSeattle/Tacoma Intl
31h 30m
1 stop
USM7:45 amKo Samui
Jun 30
USM7:45 pmKo Samui
51h 00m
1 stop
SEA8:45 amSeattle/Tacoma Intl
$972
Singapore Airlines
Mar 19
SEA9:45 amSeattle/Tacoma Intl
41h 25m
1 stop
USM5:10 pmKo Samui
Mar 26
USM8:55 amKo Samui
37h 15m
1 stop
SEA8:10 amSeattle/Tacoma Intl
$1,018
Singapore Airlines
Mar 20
SEA9:45 amSeattle/Tacoma Intl
32h 15m
1 stop
USM8:00 amKo Samui
Mar 27
USM8:55 amKo Samui
37h 15m
1 stop
SEA8:10 amSeattle/Tacoma Intl
$1,259

EVA Air flights from State of Washington to Ko Samui

Our best EVA Air deals on State of Washington to Ko Samui flight tickets
EVA Air
Mar 19
SEA11:50 pmSeattle/Tacoma Intl
26h 35m
2 stops
USM4:25 pmKo Samui
Mar 26
USM9:20 amKo Samui
23h 10m
2 stops
SEA6:30 pmSeattle/Tacoma Intl
$975
EVA Air
Jun 28
SEA1:50 amSeattle/Tacoma Intl
23h 55m
2 stops
USM3:45 pmKo Samui
Jul 16
USM10:05 amKo Samui
23h 45m
2 stops
SEA7:50 pmSeattle/Tacoma Intl
$1,585
EVA Air
Jun 24
SEA1:50 amSeattle/Tacoma Intl
29h 00m
2 stops
USM8:50 pmKo Samui
Jul 15
USM8:45 amKo Samui
25h 05m
2 stops
SEA7:50 pmSeattle/Tacoma Intl
$1,619

momondo Fare Finder

 
Customize your flight search to find flights from State of Washington 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 February 5, 2026.
Use the filters below to find and compare flights from Washington to Ko Samui that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sat 6/13

10:15 am-7:45 am

1 stop31h 30m

Ko Samui

Tue 6/30

7:45 pm-8:45 am

1 stop51h 00m

$972

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Thu 3/19

11:50 pm-4:25 pm

2 stops26h 35m

Ko Samui

Thu 3/26

9:20 am-6:30 pm

2 stops23h 10m

$975

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Thu 4/9

1:15 am-8:50 pm

2 stops29h 35m

Ko Samui

Sun 4/19

8:10 am-4:10 pm

2 stops22h 00m

$1,006

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Thu 3/19

9:45 am-5:10 pm

1 stop41h 25m

Ko Samui

Thu 3/26

8:55 am-8:10 am

1 stop37h 15m

$1,018

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 2/15

11:45 pm-9:20 pm

2 stops30h 35m

Ko Samui

Tue 2/24

8:15 am-3:05 pm

2 stops21h 50m

$1,143

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 2/15

11:45 pm-9:20 pm

2 stops30h 35m

Ko Samui

Tue 2/24

8:15 am-3:05 pm

2 stops21h 50m

$1,162

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 2/15

11:45 pm-9:20 pm

2 stops30h 35m

Ko Samui

Tue 2/24

8:15 am-3:05 pm

2 stops21h 50m

$1,183

PortlandKo Samui

PDX - USM

PDXUSM

Portland

Sat 4/18

7:05 pm-8:15 am

2 stops23h 10m

Ko Samui

Wed 4/22

4:25 pm-2:40 pm

2 stops36h 15m

$1,209

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sat 4/4

11:45 am-11:15 am

2 stops33h 30m

Ko Samui

Sun 4/19

9:00 pm-10:05 am

2 stops27h 05m

$1,228

PortlandKo Samui

PDX - USM

PDXUSM

Portland

Sat 4/18

3:42 pm-1:45 pm

3 stops32h 03m

Ko Samui

Wed 4/22

2:00 pm-10:53 pm

3 stops22h 53m

$1,232

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Ko Samui from

How to get the cheapest flight ticket from State of Washington 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 Tuesday is the least expensive day to fly to Ko Samui. Tickets to fly out on this day can be as low as $275. Flights from State of Washington to Ko Samui on a Sunday will generally be more expensive and average around $548. 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 State of Washington to Ko Samui flights are usually those with departure times in the afternoon. Our users have found flights to Ko Samui in the afternoon for as low as $304. In the evening is when there is more demand to fly to Ko Samui, so prices are often more expensive at around $454 per ticket.

Can stopping save me money on State of Washington to Ko Samui flights?

You could potentially save up to 44% on your flight if you consider stops on a State of Washington to Ko Samui flight.

Cheap State of Washington to Ko Samui flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from State of Washington to Ko Samui

Fastest flight time

22h 15m

Direct flights

None
The fastest flight from State of Washington to Ko Samui takes 22h 15m
There are no direct flights from State of Washington to Ko Samui. There are no popular flight routes from State of Washington to Ko Samui.
Search flight deals

  • When did momondo last update prices for flights from Washington to Ko Samui Airport?

    Prices for flights from Washington to Ko Samui Airport were last updated today.

  • How many operators does momondo search for flights from Washington to Ko Samui Airport?

  • How old do you have to be to fly from Washington to Ko Samui Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Washington to Ko Samui Airport.

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

    The travel and health documents you'll need for your trip to Ko Samui Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Ko Samui Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Best airlines flying from State of Washington to Ko Samui

Compare and see reviews for airlines that fly from State of Washington to Ko Samui with momondo
Airline
Rating
Free Cancellation
Price
Singapore AirlinesPriceFrom $859Free CancellationRating
8.2
1,448 reviews
Search Singapore Airlines flights

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
Khanom

Why use momondo?

Why should I use momondo to find a flight deal from Washington to Ko Samui?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Washington to Ko Samui. momondo saves you time and could save you money on your trip.

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

Yes. All flights to Ko Samui from Washington on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Washington 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.

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

Price alerts on flights to Ko Samui from Washington 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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