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Cardiff

$750+ Cheap flights from Seattle (SEA) to Cardiff (CWL)

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 12/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — CWL
Dec 6 — Dec 131
Sat 12/6
Sat 12/13
1 adult, Economy
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Find flight deals from Seattle to Cardiff

Cheapest flights from Seattle to Cardiff
Explore the most affordable flight options available from Seattle to Cardiff. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 6, 2025.

This KLM deal was found by Cheapflights users on 11/6. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/43:05 pmSEA - CWL
1 stop17h 40mKLM
Thu 12/1110:20 amCWL - SEA
1 stop33h 30mKLM
Deal found 11/6$750
This Delta deal was found by Cheapflights users on 11/6. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/49:30 amSEA - CWL
2 stops23h 15mDelta
Thu 12/1110:20 amCWL - SEA
2 stops20h 05mDelta
Deal found 11/6$764
This Mytrip deal was found by Cheapflights users on 11/6. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/42:35 pmSEA - CWL
2 stops23h 25mMultiple Airlines
Thu 12/118:35 amCWL - SEA
3 stops35h 35mMultiple Airlines
Deal found 11/6$1,566

Cheap flight deals from Seattle to Cardiff

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Cardiff (CWL). 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 November 6, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
1 star

Round-trip from

$750
(KLM)
Provider with most accurate pricing for Seattle/Tacoma Intl-Cardiff Wales flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Cardiff Wales flights.
Search Deals
From Seattle/Tacoma Intl to Cardiff Wales
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Cardiff 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 November 6, 2025.
Use the filters below to find and compare flights from Seattle to Cardiff that are best for you.

Fly from

Seattle

Fly to

Cardiff

Route

Depart

Return

Price

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 12/4

3:05 pm-4:45 pm

1 stop17h 40m

Cardiff Wales

Thu 12/11

10:20 am-11:50 am

1 stop33h 30m

$750

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 12/4

9:30 am-4:45 pm

2 stops23h 15m

Cardiff Wales

Thu 12/11

10:20 am-10:25 pm

2 stops20h 05m

$764

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 4/30

5:35 pm-4:45 pm

1 stop15h 10m

Cardiff Wales

Mon 5/4

9:50 am-11:35 am

1 stop33h 45m

$924

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/6

  • Most accurate provider: When it comes to deals on Seattle-Cardiff flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Cardiff flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Cardiff flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Cardiff 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-Cardiff 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 Cardiff

Have a flexible travel schedule? Discover the best time to fly to Cardiff 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 Cardiff

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

Find hourly flight availability from Seattle to Cardiff. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 6, 2025.

When flying from Seattle to Cardiff, the time of day you fly usually plays a role in the price. Save by searching for a flight at noon, which can drop the price by up to 42% versus a flight in the evening.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Cardiff. 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 Cardiff?

    Departing from Seattle to Cardiff will take you 17h 40m. There are 4709 mi between Seattle and Cardiff. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

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

  • How can I find direct flights from Seattle to Cardiff?

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

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

    Yes. Cheapflights offers flight deals from Seattle to Cardiff 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

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