Cardiff

$579+ 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 8/25. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — CWL
Jul 8 — Jul 151
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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 July 3, 2025.

Round-trip from

$579
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$1,649
From Seattle/Tacoma Intl to Cardiff Wales
Highest demand for flights based on searches. 21% potential increase in price ($319 potential increase over avg. RT price).
Cheapest flight prices on average. 4% potential price decrease ($55 potential savings vs. average RT price).
Average for round-trip flights in July 2025

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 July 3, 2025.

This Kiwi.com deal was found by Cheapflights users on 7/1. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/257:35 pmSEA - CWL
1 stop12h 20mMultiple Airlines
Mon 9/11:10 pmCWL - SEA
1 stop12h 40mMultiple Airlines
Deal found 7/1$579
This Ticket deal was found by Cheapflights users on 7/1. 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 Ticket is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/255:30 amSEA - CWL
2 stops43h 45mVirgin Atlantic
Mon 9/19:50 amCWL - SEA
2 stops55h 55mVirgin Atlantic
Deal found 7/1$879
This Delta deal was found by Cheapflights users on 6/30. 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.
Fri 8/159:40 amSEA - CWL
2 stops23h 25mDelta
Fri 8/229:50 amCWL - SEA
1 stop14h 05mDelta
Deal found 6/30$981
This KLM deal was found by Cheapflights users on 6/30. 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.
Fri 8/155:40 pmSEA - CWL
1 stop31h 35mKLM
Fri 8/229:50 amCWL - SEA
1 stop14h 05mKLM
Deal found 6/30$1,014

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 July 3, 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

Mon 8/25

7:35 pm-3:55 pm

1 stop12h 20m

Cardiff Wales

Mon 9/1

1:10 pm-5:50 pm

1 stop12h 40m

$579

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/25

5:30 am-9:15 am

2 stops43h 45m

Cardiff Wales

Mon 9/1

9:50 am-9:45 am

2 stops55h 55m

$879

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Fri 8/15

9:40 am-5:05 pm

2 stops23h 25m

Cardiff Wales

Fri 8/22

9:50 am-3:55 pm

1 stop14h 05m

$981

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Fri 8/15

5:40 pm-9:15 am

1 stop31h 35m

Cardiff Wales

Fri 8/22

9:50 am-3:55 pm

1 stop14h 05m

$1,014

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/7

5:05 pm-2:20 pm

3 stops37h 15m

$1,069

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/7

2:10 pm-4:45 pm

1 stop18h 35m

$1,380

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/2

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 July 3, 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 in the morning, which can drop the price by up to 17% versus a flight at noon.

Reviews of airlines servicing Cardiff

Get insights into the airlines that provide service to Cardiff. 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 Cardiff. Reviews last updated July 3, 2025.
Read reviews from past customers who have flown Delta, KLM, and Virgin Atlantic from Seattle to Cardiff. 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.
8.0
Very good

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Entertainment

7.9

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
8.0
Very good
8.0
Very good

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Entertainment

7.9

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
8.0
Very good

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Entertainment

7.9

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
8.0
Very good

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Entertainment

7.9

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

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.
  • What are the cheapest airlines flying from Seattle to Cardiff round-trip?

    Cheapflights users have booked flights from Seattle to Cardiff round-trip from $879. Other airlines that can offer you cheap pricing are Delta, from $981, and KLM, from $1,014. These flights start at 23% lower than the current average price 3 months from now.

  • 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.

  • What is the cheapest month to book a flight from Seattle to Cardiff?

    Currently, February is the cheapest month in which you can book a flight from Seattle to Cardiff (average of $773). Flying from Seattle to Cardiff in June is currently the most expensive (average of $1,622). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Alternative routes for Seattle to Cardiff

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Top airline flying from Seattle to Cardiff

Discover the top airline that operate flights from Seattle to Cardiff. 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 July 3, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$760Average$1,132FlexibilityNo cancel feeOn-time75%

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