$739 Cheap Flights from Cardiff (CWL) to Seattle (SEA)

View $739 flight on Mon, Jan 26, 2026Opens in a new window

Popular airlines from Cardiff International Airport (CWL) to Seattle-Tacoma International Airport (SEA)

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Cheap Flights from Cardiff to Seattle (CWL-SEA)

Prices were available within the past 7 days and start at $739 for one-way flights and $1,166 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Loganair
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,166 Roundtrip, found 5 days ago
$1,166
Roundtrip
found 5 days ago
Select Loganair flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,166 found 5 days ago
Aer Lingus
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,175 Roundtrip, found 5 days ago
$1,175
Roundtrip
found 5 days ago
Select Aer Lingus flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,175 found 5 days ago
British Airways
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,181 Roundtrip, found 5 days ago
$1,181
Roundtrip
found 5 days ago
Select British Airways flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,181 found 5 days ago
Aer Lingus
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,187 Roundtrip, found 5 days ago
$1,187
Roundtrip
found 5 days ago
Select Aer Lingus flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,187 found 5 days ago
Loganair
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,202 Roundtrip, found 5 days ago
$1,202
Roundtrip
found 5 days ago
Select Loganair flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,202 found 5 days ago
Aer Lingus
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,203 Roundtrip, found 5 days ago
$1,203
Roundtrip
found 5 days ago
Select Aer Lingus flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,203 found 5 days ago
British Airways
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,209 Roundtrip, found 5 days ago
$1,209
Roundtrip
found 5 days ago
Select British Airways flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,209 found 5 days ago
British Airways
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,316 Roundtrip, found 5 days ago
$1,316
Roundtrip
found 5 days ago
Select British Airways flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,316 found 5 days ago
Aer Lingus
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,338 Roundtrip, found 5 days ago
$1,338
Roundtrip
found 5 days ago
Select Aer Lingus flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,338 found 5 days ago
British Airways
Wed, Dec 3 - Wed, Dec 10
CWL
Cardiff
SEA
Seattle
$1,450 Roundtrip, found 5 days ago
$1,450
Roundtrip
found 5 days ago
Select British Airways flight, departing Wed, Dec 3 from Cardiff to Seattle, returning Wed, Dec 10, priced at $1,450 found 5 days ago

Frequently asked questions

How much does a flight from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA) cost?
Secure a cheap one-way flight from $739 or cheap return flight from $1,166 from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA)?
December is the least expensive month to fly from CWL to SEA. Traveling during an off-peak travel window is often the key to finding better deals on flights.
How many flights per day from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA)?
You'll have to catch a flight with a layover when traveling from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA). Direct flights don't operate daily on this route. However, just filter your search to include one or more stops to find the best option for your trip.
What day of the week has the most flights from CWL to SEA?
Typically you'll find the most flight options available on a Friday. Tuesdays tend to be the quietest.* But this can vary depending on the time of year, carrier and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA)?
Opt for a flight from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA) that leaves before 3 PM to reduce the likelihood of delays. Departures after this hour are on average 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA) last-minute?
Holding off until right before your break to book a ticket from CWL to SEA often results in higher prices. While you might find some last-minute deals, there's no guarantee. Be flexible with your itinerary for the best chance of snagging a bargain.
Is it cheaper to book a CWL to SEA flight and hotel package?
Booking a CWL to SEA flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your travels all in one place. Select from our impressive range of accommodations and then add flights, activities and car rentals to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Cardiff Intl. Airport (CWL) to Seattle - Tacoma Intl. Airport (SEA)?
If you reserved your CWL to SEA flight within the last 24 hours, you may be able to cancel or modify it without fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, visit our Customer Service portal if you'd like more information.

Travel information

Origin airport
Cardiff Intl.
Destination airport
Seattle - Tacoma Intl.
Roundtrip price
$1,165
Distance
4712 mi

Book with confidence

Cardiff to Seattle Flights

The cheapest times to fly from Cardiff to Seattle

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Cardiff to Seattle are during the month of December. You can find some of the cheapest flights from Cardiff to Seattle with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Cardiff to Seattle

Sunday is one of the best days to book for cheap flights from Cardiff to Seattle: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Cardiff to Seattle

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Cardiff to Seattle in 2025. You can also book with separate airlines for your outbound and return journeys, from $739 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Cardiff to Seattle flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Cardiff to Seattle airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Cardiff to Seattle Flights

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