What is the cheapest airline that flies from Washington to Ko Samui?

EVA Air and Cathay Pacific are the most popular carriers operating from Washington to Ko Samui

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?

As of August 2025, there are 2 operators available to choose from 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.

$583 Cheap Flights from Washington to Ko Samui in 2025

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Find the cheapest flights from Washington to Ko Samui

Round-trip

One-way

Cheap round-trip flights

12:30 pm - 7:10 amSEA-USM

27h 40m2 stops

7:35 pm - 9:55 amUSM-SEA

29h 20m2 stops

$827

Find Deal

Tue, Jan 20 - Tue, Jan 27

9:40 am - 7:45 amPDX-USM

31h 05m3 stops

8:20 pm - 1:46 pmUSM-PDX

32h 26m3 stops

$948

Find Deal

Thu, Jan 22 - Tue, Jan 27

12:10 am - 3:35 pmSEA-USM

24h 25m2 stops

1:45 pm - 5:40 pmUSM-SEA

18h 55m2 stops

$997EVA Air

Find Deal

Mon, Jan 19 - Tue, Jan 27

12:30 am - 8:30 pmSEA-USM

30h 00m2 stops

9:15 am - 7:30 pmUSM-SEA

24h 15m2 stops

$1,042EVA Air

Find Deal

Tue, Sep 30 - Wed, Oct 8

10:15 am - 4:45 pmSEA-USM

40h 30m1 stop

5:40 pm - 8:45 amUSM-SEA

29h 05m1 stop

$1,049Singapore Airlines

Find Deal

Sun, Oct 19 - Wed, Oct 22

12:30 am - 3:10 pmSEA-USM

24h 40m2 stops

2:00 pm - 7:30 pmUSM-SEA

19h 30m2 stops

$1,104EVA Air

Find Deal

Sat, Oct 18 - Wed, Oct 22

1:30 pm - 8:15 amSEA-USM

28h 45m2 stops

9:00 pm - 10:25 amUSM-SEA

27h 25m2 stops

$1,230Japan Airlines

Find Deal

Sun, Oct 19 - Wed, Oct 22

8:45 am - 6:50 pmSEA-USM

43h 05m1 stop

7:45 pm - 7:10 amUSM-SEA

50h 25m1 stop

$1,257Singapore Airlines

Find Deal

Tue, Jan 20 - Tue, Jan 27

4:30 pm - 10:30 amSEA-USM

52h 00m2 stops

2:30 pm - 12:45 pmUSM-SEA

36h 15m2 stops

$1,326Qatar Airways

Find Deal

Wed, Oct 1 - Wed, Oct 8

10:40 am - 10:40 amPDX-USM

33h 00m3 stops

7:00 pm - 4:27 pmUSM-PDX

36h 27m3 stops

$3,445Qatar Airways

Find Deal

Thu, Dec 25 - Fri, Jan 2

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

Jan 19

SEA12:10 amSeattle/Tacoma Intl

24h 25m

2 stops

USM3:35 pmKo Samui

Jan 27

USM1:45 pmKo Samui

18h 55m

2 stops

SEA5:40 pmSeattle/Tacoma Intl

$997

Find similar

EVA Air

Sep 30

SEA12:30 amSeattle/Tacoma Intl

30h 00m

2 stops

USM8:30 pmKo Samui

Oct 8

USM9:15 amKo Samui

24h 15m

2 stops

SEA7:30 pmSeattle/Tacoma Intl

$1,042

Find similar

EVA Air

Oct 18

SEA12:30 amSeattle/Tacoma Intl

24h 40m

2 stops

USM3:10 pmKo Samui

Oct 22

USM2:00 pmKo Samui

19h 30m

2 stops

SEA7:30 pmSeattle/Tacoma Intl

$1,104

Find similar

Qatar Airways flights from State of Washington to Ko Samui

Our best Qatar Airways deals on State of Washington to Ko Samui flight tickets

Qatar Airways

Oct 1

SEA4:30 pmSeattle/Tacoma Intl

52h 00m

2 stops

USM10:30 amKo Samui

Oct 8

USM2:30 pmKo Samui

36h 15m

2 stops

SEA12:45 pmSeattle/Tacoma Intl

$1,326

Find similar

Qatar Airways

Dec 25

PDX10:40 amPortland

33h 00m

3 stops

USM10:40 amKo Samui

Jan 2

USM7:00 pmKo Samui

36h 27m

3 stops

PDX4:27 pmPortland

$3,445

Find similar

Qatar Airways

Dec 25

PDX10:40 amPortland

33h 00m

3 stops

USM10:40 amKo Samui

Jan 2

USM6:30 pmKo Samui

37h 27m

3 stops

PDX4:57 pmPortland

$3,519

Find similar

Fly from

Fly to

Route

Depart

Return

Price

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Tue 1/20

12:30 pm-7:10 am

2 stops27h 40m

Ko Samui

Tue 1/27

7:35 pm-9:55 am

2 stops29h 20m

$827

PortlandKo Samui

PDX - USM

PDXUSM

Portland

Thu 1/22

9:40 am-7:45 am

3 stops31h 05m

Ko Samui

Tue 1/27

8:20 pm-1:46 pm

3 stops32h 26m

$948

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Mon 1/19

12:10 am-3:35 pm

2 stops24h 25m

Ko Samui

Tue 1/27

1:45 pm-5:40 pm

2 stops18h 55m

$997

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Tue 9/30

12:30 am-8:30 pm

2 stops30h 00m

Ko Samui

Wed 10/8

9:15 am-7:30 pm

2 stops24h 15m

$1,042

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 10/19

10:15 am-4:45 pm

1 stop40h 30m

Ko Samui

Wed 10/22

5:40 pm-8:45 am

1 stop29h 05m

$1,049

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sat 10/18

12:30 am-3:10 pm

2 stops24h 40m

Ko Samui

Wed 10/22

2:00 pm-7:30 pm

2 stops19h 30m

$1,104

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 10/19

1:30 pm-8:15 am

2 stops28h 45m

Ko Samui

Wed 10/22

9:00 pm-10:25 am

2 stops27h 25m

$1,230

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Tue 1/20

8:45 am-6:50 pm

1 stop43h 05m

Ko Samui

Tue 1/27

7:45 pm-7:10 am

1 stop50h 25m

$1,257

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Wed 10/1

4:30 pm-10:30 am

2 stops52h 00m

Ko Samui

Wed 10/8

2:30 pm-12:45 pm

2 stops36h 15m

$1,326

PortlandKo Samui

PDX - USM

PDXUSM

Portland

Thu 12/25

10:40 am-10:40 am

3 stops33h 00m

Ko Samui

Fri 1/2

7:00 pm-4:27 pm

3 stops36h 27m

$3,445

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 16 resultsSorted by cheapest first

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

Prices

Airlines

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.

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

Best Price Found	$583
Fastest flight time	21h 20m
Direct flights	None
Airports in Ko Samui	1 airport

The best one-way flight to Ko Samui from State of Washington in the past 72 hours is $583. The best round-trip flight deal from State of Washington to Ko Samui found on momondo in the last 72 hours is $827.

The fastest flight from State of Washington to Ko Samui takes 21h 20m

There are no direct flights from State of Washington to Ko Samui. Popular non-direct routes for this connection are Portland Airport - Ko Samui Airport and Seattle/Tacoma Intl Airport - Ko Samui Airport.

There is 1 airport near Ko Samui: Ko Samui (USM)

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?
As of August 2025, there are 2 operators available to choose from 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 Airlines	PriceFrom $859	Free Cancellation	Rating 8.1 1,347 reviews		Search Singapore Airlines flights
EVA Air	PriceFrom $999	Free Cancellation	Rating 8.4 1,232 reviews		Search EVA Air flights

Ko Pha Ngan

Ko Tao

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.