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Cheap flights from Seattle to Cardiff from $1,067

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Cardiff departing on 9/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Seattle to Cardiff

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
7:10 pm - 11:25 pm
SEA
-
CWL
20h 15m
1 stop
Multiple Airlines Logo
10:10 pm - 5:10 pm
CWL
-
SEA
27h 00m
1 stop
$1,067Multiple Airlines
Tue, Sep 1 - Mon, Sep 14
KLM Logo
5:40 pm - 9:15 am
SEA
-
CWL
31h 35m
1 stop
KLM Logo
9:45 am - 11:37 am
CWL
-
SEA
33h 52m
1 stop
$1,087KLM
Sun, May 17 - Mon, Jun 1
Delta Logo
9:50 am - 4:45 pm
SEA
-
CWL
22h 55m
2 stops
Delta Logo
9:45 am - 8:41 pm
CWL
-
SEA
18h 56m
2 stops
$1,136Delta
Tue, Sep 1 - Mon, Sep 14
Multiple Airlines Logo
7:10 pm - 9:45 pm
SEA
-
CWL
18h 35m
1 stop
Multiple Airlines Logo
10:10 pm - 7:19 pm
CWL
-
SEA
29h 09m
2 stops
$1,155Multiple Airlines
Sun, May 17 - Mon, Jun 1
KLM Logo
1:50 pm - 5:05 pm
SEA
-
CWL
19h 15m
1 stop
KLM Logo
9:45 am - 8:41 pm
CWL
-
SEA
18h 56m
2 stops
$1,161KLM
Fri, May 1 - Fri, May 8
Delta Logo
1:45 pm - 4:45 pm
SEA
-
CWL
19h 00m
1 stop
Delta Logo
9:45 am - 4:30 pm
CWL
-
SEA
14h 45m
1 stop
$1,193Delta
Wed, Apr 8 - Thu, Apr 16
KLM Logo
4:55 pm - 4:45 pm
SEA
-
CWL
15h 50m
2 stops
KLM Logo
9:45 am - 11:45 am
CWL
-
SEA
34h 00m
1 stop
$1,194KLM
Wed, Apr 8 - Thu, Apr 16
KLM Logo
8:25 am - 9:15 am
SEA
-
CWL
16h 50m
2 stops
KLM Logo
9:45 am - 9:50 pm
CWL
-
SEA
20h 05m
2 stops
$1,199KLM
Wed, Apr 8 - Thu, Apr 16
WestJet Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
2 stops
WestJet Logo
11:35 am - 7:31 am
CWL
-
SEA
27h 56m
2 stops
$1,200WestJet
Sat, May 30 - Tue, Jun 30
KLM Logo
1:50 pm - 5:05 pm
SEA
-
CWL
19h 15m
1 stop
KLM Logo
5:15 pm - 4:30 pm
CWL
-
SEA
31h 15m
1 stop
$1,201KLM
Fri, May 1 - Fri, May 8

Delta flights from Seattle to Cardiff

Our best Delta deals on Seattle to Cardiff flight tickets
Delta
Sep 1
SEA9:50 amSeattle/Tacoma Intl
22h 55m
2 stops
CWL4:45 pmCardiff Wales
Sep 14
CWL9:45 amCardiff Wales
18h 56m
2 stops
SEA8:41 pmSeattle/Tacoma Intl
$1,136
Delta
Apr 8
SEA1:45 pmSeattle/Tacoma Intl
19h 00m
1 stop
CWL4:45 pmCardiff Wales
Apr 16
CWL9:45 amCardiff Wales
14h 45m
1 stop
SEA4:30 pmSeattle/Tacoma Intl
$1,193
Delta
Mar 23
SEA7:20 amSeattle/Tacoma Intl
19h 30m
2 stops
CWL9:50 amCardiff Wales
Apr 6
CWL9:45 amCardiff Wales
20h 30m
2 stops
SEA10:15 pmSeattle/Tacoma Intl
$1,208

KLM flights from Seattle to Cardiff

Our best KLM deals on Seattle to Cardiff flight tickets
KLM
May 17
SEA5:40 pmSeattle/Tacoma Intl
31h 35m
1 stop
CWL9:15 amCardiff Wales
Jun 1
CWL9:45 amCardiff Wales
33h 52m
1 stop
SEA11:37 amSeattle/Tacoma Intl
$1,087
KLM
Mar 23
SEA7:20 amSeattle/Tacoma Intl
19h 30m
2 stops
CWL9:50 amCardiff Wales
Apr 6
CWL9:45 amCardiff Wales
34h 00m
1 stop
SEA11:45 amSeattle/Tacoma Intl
$1,148
KLM
May 1
SEA1:50 pmSeattle/Tacoma Intl
19h 15m
1 stop
CWL5:05 pmCardiff Wales
May 8
CWL9:45 amCardiff Wales
18h 56m
2 stops
SEA8:41 pmSeattle/Tacoma Intl
$1,161

momondo 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, momondo users made 832,500 searches. Data last updated March 22, 2026.
Use the filters below to find and compare flights from Seattle to Cardiff that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 9/1

7:10 pm-11:25 pm

1 stop20h 15m

Cardiff Wales

Mon 9/14

10:10 pm-5:10 pm

1 stop27h 00m

$1,067

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Sun 5/17

5:40 pm-9:15 am

1 stop31h 35m

Cardiff Wales

Mon 6/1

9:45 am-11:37 am

1 stop33h 52m

$1,087

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 9/1

9:50 am-4:45 pm

2 stops22h 55m

Cardiff Wales

Mon 9/14

9:45 am-8:41 pm

2 stops18h 56m

$1,136

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Sun 5/17

7:10 pm-9:45 pm

1 stop18h 35m

Cardiff Wales

Mon 6/1

10:10 pm-7:19 pm

2 stops29h 09m

$1,155

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Fri 5/1

1:50 pm-5:05 pm

1 stop19h 15m

Cardiff Wales

Fri 5/8

9:45 am-8:41 pm

2 stops18h 56m

$1,161
Quickest round-trip

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Wed 4/8

1:45 pm-4:45 pm

1 stop19h 00m

Cardiff Wales

Thu 4/16

9:45 am-4:30 pm

1 stop14h 45m

$1,193

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Wed 4/8

4:55 pm-4:45 pm

2 stops15h 50m

Cardiff Wales

Thu 4/16

9:45 am-11:45 am

1 stop34h 00m

$1,194

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Wed 4/8

8:25 am-9:15 am

2 stops16h 50m

Cardiff Wales

Thu 4/16

9:45 am-9:50 pm

2 stops20h 05m

$1,199

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Sat 5/30

7:35 pm-10:15 am

2 stops30h 40m

Cardiff Wales

Tue 6/30

11:35 am-7:31 am

2 stops27h 56m

$1,200

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Fri 5/1

1:50 pm-5:05 pm

1 stop19h 15m

Cardiff Wales

Fri 5/8

5:15 pm-4:30 pm

1 stop31h 15m

$1,201

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to Cardiff from

How to get the cheapest flight ticket from Seattle to Cardiff

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

What airlines fly to Cardiff?

Delta, Aer Lingus and KLM are the top three most popular airlines that fly to Cardiff from Seattle according to our data. Delta is the first choice among our users, with 39% of people opting to fly with this airline when traveling to Cardiff. Keep in mind that there are 3 different airlines that fly to Cardiff on a routine basis, so you have a few additional options to choose from.

When to book flights from Seattle to Cardiff

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to Cardiff according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to Cardiff (SEA to CWL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to Cardiff

Fastest flight time

19h 00m

Direct flights

None
The fastest flight from Seattle to Cardiff takes 19h 00m
There are no direct flights from Seattle to Cardiff. There are no popular flight routes from Seattle to Cardiff.
Search flight deals

  • How far is Seattle/Tacoma Intl to Cardiff Wales by plane?

    The straight-line distance from Seattle/Tacoma Intl to Cardiff Wales is 4700.6 mi. In terms of flight time, this usually takes a little over 19h 00m.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Cardiff Wales Airport?

    Prices for flights from Seattle/Tacoma Intl Airport to Cardiff Wales Airport refresh daily.

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Cardiff Wales Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Cardiff Wales Airport.

  • What documentation or ID do you need to fly to Cardiff Wales Airport?

    The necessary travel and health documents for your Cardiff Wales Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to Cardiff?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to Cardiff. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Seattle to Cardiff with flexible booking policies on momondo?

momondo does allow users to show only those flights to Cardiff from Seattle which offer a flexible booking policy as well as other useful filters and features.

How can momondo help me find flights from Seattle to Cardiff?

Once all potential Seattle to Cardiff flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

I’m not ready to book a flight from Seattle to Cardiff right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Cardiff, momondo offers a useful price alert feature which will track prices for flights to Cardiff from Seattle and alert you when they change.

An easier way to manage your Cardiff trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
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Find better results for your trip to the United Kingdom

Fly your favorite airline to Cardiff

Airlines are sorted and displayed according to clicks in the past 7 days on momondo
Delta
Aer Lingus
KLM