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Ko Samui

$502+ Cheap flights from Seattle (SEA) to Ko Samui (USM)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 1/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — USM
Nov 9 — Nov 161
Sun 11/9
Sun 11/16
1 adult, Economy
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Cheap flight deals from Seattle to Ko Samui

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) 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 October 10, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$818
(Justfly.com)

One-way from

$502
(Trip.com)

Popular in

June

Cheapest in

November
Provider with most accurate pricing for Seattle/Tacoma Intl-Ko Samui flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Ko Samui flights.
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From Seattle/Tacoma Intl to Ko Samui
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One-way flight from Seattle/Tacoma Intl to Ko Samui
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Highest demand for flights based on searches. 21% potential increase in price ($335 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease ($52 potential savings vs. average RT price).
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Find flight deals from Seattle to Ko Samui

Cheapest flights from Seattle to Ko Samui
Explore the most affordable flight options available from Seattle to Ko Samui. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 10, 2025.

This Singapore Airlines deal was found by Cheapflights users on 10/9. 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 Singapore Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/78:45 amSEA - USM
1 stop32h 15mSingapore Airlines
Mon 12/88:55 amUSM - SEA
1 stop37h 15mSingapore Airlines
Deal found 10/9$935
This Gotogate deal was found by Cheapflights users on 10/9. 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.
Fri 11/711:45 pmSEA - USM
2 stops24h 50mMultiple Airlines
Mon 12/89:20 amUSM - SEA
2 stops20h 45mMultiple Airlines
Deal found 10/9$968
This EVA Air deal was found by Cheapflights users on 10/8. 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 EVA Air is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/2912:10 amSEA - USM
2 stops24h 25mEVA Air
Thu 12/41:35 pmUSM - SEA
2 stops18h 55mEVA Air
Deal found 10/8$1,073
This Singapore Airlines deal was found by Cheapflights users on 10/7. 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 Singapore Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/308:45 amSEA - USM
1 stop32h 15mSingapore Airlines
Thu 12/47:45 pmUSM - SEA
1 stop26h 25mSingapore Airlines
Deal found 10/7$1,203
This Cathay Pacific deal was found by Cheapflights users on 10/8. 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 Cathay Pacific is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/307:56 pmSEA - USM
2 stops32h 39mCathay Pacific
Thu 12/411:40 amUSM - SEA
2 stops25h 19mCathay Pacific
Deal found 10/8$1,256

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle 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 October 10, 2025.
Use the filters below to find and compare flights from Seattle to Ko Samui that are best for you.

Fly from

Seattle

Fly to

Ko Samui

Route

Depart

Return

Price

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Fri 11/7

8:45 am-8:00 am

1 stop32h 15m

Ko Samui

Mon 12/8

8:55 am-7:10 am

1 stop37h 15m

$935

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Fri 11/7

11:45 pm-3:35 pm

2 stops24h 50m

Ko Samui

Mon 12/8

9:20 am-3:05 pm

2 stops20h 45m

$968

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sat 11/29

12:10 am-3:35 pm

2 stops24h 25m

Ko Samui

Thu 12/4

1:35 pm-5:30 pm

2 stops18h 55m

$1,073

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 11/30

8:45 am-8:00 am

1 stop32h 15m

Ko Samui

Thu 12/4

7:45 pm-7:10 am

1 stop26h 25m

$1,203

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Sun 11/30

7:56 pm-7:35 pm

2 stops32h 39m

Ko Samui

Thu 12/4

11:40 am-9:59 pm

2 stops25h 19m

$1,256

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Tue 10/14

7:59 pm-7:50 am

3 stops45h 51m

$630

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Tue 10/14

8:00 am-6:35 pm

2 stops44h 35m

$680

SeattleKo Samui

SEA - USM

SEAUSM

Seattle/Tacoma Intl

Tue 10/14

10:15 am-7:50 am

1 stop31h 35m

$838

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/8

Compare providers for flights from Seattle 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 Seattle to Ko Samui in October.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 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 Seattle-Ko Samui flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Ko Samui flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Ko Samui flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Ko Samui flights, Cheapflights users trust FlightHub the most. FlightHub 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 Seattle-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 Seattle to Ko Samui

Have a flexible travel schedule? Discover the best time to fly to Ko Samui from Seattle 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 Seattle to Ko Samui

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

Find hourly flight availability from Seattle 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 October 10, 2025.

When flying from Seattle to Ko Samui, the time of day you fly usually plays a role in the price. Save by searching for a flight in the afternoon, which can drop the price by up to 33% versus a flight in the evening.

What is the cheapest day to fly from Seattle to Ko Samui?

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

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

The best insider tips for Seattle to Ko Samui flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to Ko Samui trip
Airlines
Alaska Airlines

Enjoy free cocktails in Premium Class, though snacks and meals require purchase or pre-order.


Alaska Airlines offers Wi-Fi for a flat fee, ideal for long flights to stay productive.

Read more about Alaska Airlinesby Robert Schrader
Sun Country Air

Sun Country's priority check-in includes access to priority security lanes for a smoother experience.


Sun Country offers free inflight entertainment streamed to your device, but no onboard internet access.

Read more about Sun Country Airby Jennifer Simonson
Our travel experts
Robert Schrader

Robert Schrader

Expert on Alaska Airlines

Robert Schrader

Robert Schrader

One of the web's original travel bloggers, Robert launched his first site Leave Your Daily Hell in 2009. Since then, he's expanded into destination niche sites (one each for Japan, Thailand and Taiwan), in addition to having written for the inflight magazines of Singapore Airlines and Korean Air. Overall, he's visited nearly 100 countries, and flies business as often as possible.

Read more
Jennifer Simonson

Jennifer Simonson

Expert on Sun Country Air

Jennifer Simonson

Jennifer Simonson

Jennifer Simonson is driven by her lifelong commitment to exploring the globe. Her insatiable curiosity had led her to immerse herself into diverse locations like Oklahoma City and Pismo. Her hotel recommendations are the result of the myriad hotels she's stayed at across her travels. Along her journey, she cherishes engaging conversations with locals, indulging in the finest ice cream, trying her hand at surfing, and embarking on nature-filled hikes.

Read more

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 October 10, 2025.
Read reviews from past customers who have flown EVA Air and Singapore Airlines from Seattle to Ko Samui. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
EVA Air
8.4
Very good
1,249 reviews

Overall

8.4

Boarding

8.4

Crew

8.6

Entertainment

8.0

Comfort

8.3

Food

8.0

Reviews

1 / 20
6.0
Good

Anonymous,Aug 2025

BKK - TPE

I bought tickets for myself and my friend and had to argue with the checkin person to get our seats together for the return flights I purchased the tickets together weeks ahead of time and did not expect to have to ask for a supervisor to sit together very disappointed in booking through kayak
EVA Air
8.4
Very good
1,249 reviews
EVA Air
8.4
Very good
1,249 reviews

Overall

8.4

Boarding

8.4

Crew

8.6

Entertainment

8.0

Comfort

8.3

Food

8.0

Reviews

1 / 20
6.0
Good

Anonymous,Aug 2025

BKK - TPE

I bought tickets for myself and my friend and had to argue with the checkin person to get our seats together for the return flights I purchased the tickets together weeks ahead of time and did not expect to have to ask for a supervisor to sit together very disappointed in booking through kayak
Singapore Airlines
8.1
Very good
1,377 reviews
EVA Air
8.4
Very good
1,249 reviews

Overall

8.4

Boarding

8.4

Crew

8.6

Entertainment

8.0

Comfort

8.3

Food

8.0

Reviews

1 / 20
6.0
Good

Anonymous,Aug 2025

BKK - TPE

I bought tickets for myself and my friend and had to argue with the checkin person to get our seats together for the return flights I purchased the tickets together weeks ahead of time and did not expect to have to ask for a supervisor to sit together very disappointed in booking through kayak

Related info for your journey

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

  • How long is the flight from Seattle to Ko Samui?

    Departing from Seattle to Ko Samui will take you 24h 25m. Seattle and Ko Samui are separated by a distance of 7715 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines flying from Seattle to Ko Samui round-trip?

    Singapore Airlines, at $859, was found to be the cheapest airline from Seattle to Ko Samui. An alternate airline flying to your destination would be EVA Air. You may be able to fly from Seattle to Ko Samui for 30% less than the average price by searching for these airlines.

  • Can I find deals for flights from Seattle to Ko Samui that include hotel bookings?

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

  • How can I find direct flights from Seattle to Ko Samui?

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

  • Can I find deals for business class flights from Seattle to Ko Samui?

    Yes. Cheapflights offers flight deals from Seattle 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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Top 2 airlines flying from Seattle to Ko Samui

Discover the top 2 airlines that operate flights from Seattle to Ko Samui. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
Singapore AirlinesCheapest$859Average$1,051FlexibilityNo cancel feeOn-time81%
EVA AirCheapest$999Average$1,351FlexibilityNo cancel feeOn-time74%

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