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Cheap flights from Seattle to Cardiff from $948

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 7/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Find the cheapest flights from Seattle to Cardiff

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
3 stops
Multiple Airlines Logo
11:35 am - 10:42 pm
CWL
-
SEA
19h 07m
3 stops
$948Multiple Airlines
Tue, Jul 7 - Tue, Jul 14
Multiple Airlines Logo
7:10 pm - 11:25 pm
SEA
-
CWL
20h 15m
1 stop
Multiple Airlines Logo
7:45 am - 6:45 pm
CWL
-
SEA
19h 00m
2 stops
$955Multiple Airlines
Tue, Sep 22 - Fri, Oct 2
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
2 stops
Multiple Airlines Logo
11:35 am - 10:42 pm
CWL
-
SEA
19h 07m
3 stops
$962Multiple Airlines
Tue, Jul 7 - Tue, Jul 14
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
2 stops
Multiple Airlines Logo
11:35 am - 10:07 am
CWL
-
SEA
30h 32m
2 stops
$980Multiple Airlines
Tue, Jul 7 - Tue, Jul 14
Multiple Airlines Logo
10:30 am - 10:15 am
SEA
-
CWL
39h 45m
2 stops
Multiple Airlines Logo
11:35 am - 7:25 pm
CWL
-
SEA
15h 50m
1 stop
$1,036Multiple Airlines
Tue, Jul 7 - Tue, Jul 14
Delta Logo
7:15 am - 9:15 am
SEA
-
CWL
18h 00m
2 stops
Delta Logo
9:45 am - 10:02 pm
CWL
-
SEA
20h 17m
2 stops
$1,061Delta
Tue, Sep 22 - Fri, Oct 2
Multiple Airlines Logo
7:10 pm - 10:50 pm
SEA
-
CWL
19h 40m
1 stop
Multiple Airlines Logo
10:10 pm - 7:25 pm
CWL
-
SEA
29h 15m
2 stops
$1,071Multiple Airlines
Mon, Aug 10 - Mon, Aug 17
Air France Logo
1:50 pm - 4:45 pm
SEA
-
CWL
18h 55m
1 stop
Air France Logo
5:15 pm - 4:27 pm
CWL
-
SEA
31h 12m
1 stop
$1,121Air France
Mon, Aug 10 - Mon, Aug 17
KLM Logo
1:50 pm - 4:45 pm
SEA
-
CWL
18h 55m
1 stop
KLM Logo
5:15 pm - 4:27 pm
CWL
-
SEA
31h 12m
1 stop
$1,124KLM
Mon, Aug 10 - Mon, Aug 17
Virgin Atlantic Logo
7:15 am - 4:45 pm
SEA
-
CWL
25h 30m
2 stops
Virgin Atlantic Logo
5:15 pm - 4:27 pm
CWL
-
SEA
31h 12m
1 stop
$1,127Virgin Atlantic
Mon, Aug 10 - Mon, Aug 17

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KLM flights from Seattle to Cardiff

Our best KLM deals on Seattle to Cardiff flight tickets
KLM
Aug 10
SEA1:50 pmSeattle/Tacoma Intl
18h 55m
1 stop
CWL4:45 pmCardiff Wales
Aug 17
CWL5:15 pmCardiff Wales
31h 12m
1 stop
SEA4:27 pmSeattle/Tacoma Intl
$1,124
KLM
Aug 14
SEA5:45 pmSeattle/Tacoma Intl
15h 20m
1 stop
CWL5:05 pmCardiff Wales
Aug 18
CWL5:15 pmCardiff Wales
26h 22m
1 stop
SEA11:37 amSeattle/Tacoma Intl
$1,157
KLM
Aug 10
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Aug 17
CWL5:15 pmCardiff Wales
31h 12m
1 stop
SEA4:27 pmSeattle/Tacoma Intl
$1,173

Delta flights from Seattle to Cardiff

Our best Delta deals on Seattle to Cardiff flight tickets
Delta
Sep 22
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Oct 2
CWL9:45 amCardiff Wales
20h 17m
2 stops
SEA10:02 pmSeattle/Tacoma Intl
$1,061
Delta
Aug 14
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Aug 18
CWL9:45 amCardiff Wales
14h 42m
1 stop
SEA4:27 pmSeattle/Tacoma Intl
$1,178
Delta
Aug 10
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Aug 17
CWL9:45 amCardiff Wales
22h 09m
2 stops
SEA11:54 pmSeattle/Tacoma Intl
$1,198

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 June 21, 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 7/7

7:35 pm-10:15 am

3 stops30h 40m

Cardiff Wales

Tue 7/14

11:35 am-10:42 pm

3 stops19h 07m

$948

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 9/22

7:10 pm-11:25 pm

1 stop20h 15m

Cardiff Wales

Fri 10/2

7:45 am-6:45 pm

2 stops19h 00m

$955

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 7/7

7:35 pm-10:15 am

2 stops30h 40m

Cardiff Wales

Tue 7/14

11:35 am-10:42 pm

3 stops19h 07m

$962

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 7/7

7:35 pm-10:15 am

2 stops30h 40m

Cardiff Wales

Tue 7/14

11:35 am-10:07 am

2 stops30h 32m

$980

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 7/7

10:30 am-10:15 am

2 stops39h 45m

Cardiff Wales

Tue 7/14

11:35 am-7:25 pm

1 stop15h 50m

$1,036
Quickest round-trip

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Tue 9/22

7:15 am-9:15 am

2 stops18h 00m

Cardiff Wales

Fri 10/2

9:45 am-10:02 pm

2 stops20h 17m

$1,061

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/10

7:10 pm-10:50 pm

1 stop19h 40m

Cardiff Wales

Mon 8/17

10:10 pm-7:25 pm

2 stops29h 15m

$1,071

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/10

1:50 pm-4:45 pm

1 stop18h 55m

Cardiff Wales

Mon 8/17

5:15 pm-4:27 pm

1 stop31h 12m

$1,121

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/10

1:50 pm-4:45 pm

1 stop18h 55m

Cardiff Wales

Mon 8/17

5:15 pm-4:27 pm

1 stop31h 12m

$1,124

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/10

7:15 am-4:45 pm

2 stops25h 30m

Cardiff Wales

Mon 8/17

5:15 pm-4:27 pm

1 stop31h 12m

$1,127

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

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

15h 20m

Direct flights

None
The fastest flight from Seattle to Cardiff takes 15h 20m
There are no direct flights from Seattle to Cardiff. There are no popular flight routes from Seattle to Cardiff.
Search flight deals

Frequently asked questions about flying from Seattle to Cardiff

  • 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 15h 20m.

  • 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.

Frequently asked questions about flying from Seattle to Cardiff

  • How do I get Price Alerts for flights from Seattle to Cardiff?

    Confirm your travel details to search for the latest offers for flights from Seattle to Cardiff. While browsing offers there will be the option to toggle “Price Alerts”. You’ll then receive updates when prices for the flight route increase or decrease.

  • How can I save money on flights from Seattle to Cardiff with momondo?

    With “Price Forecast”, learn how soon you should book your flight in advance. Down to the day of week and time of day, our information can inform you on the ideal time to book to save on your travel. Our “Price Calendar” shows you at a quick glance when to book your travel for lower rates. By setting “Price Alerts” you can monitor changes in price and target the ideal time to book. Search for your trip destination by budget amount via our “Explore” feature. Whether you’re looking for ideas for your next travel adventure or cost-cutting tips, our “Discover” content is a great place to start.

  • How does momondo find its flight prices?

    We compare prices from 700+ competitors to help you find the price that works best for you. momondo operates in over 30 international markets, bringing you access to a wide range of fares and deals. Search for your travel using momondo for a diverse range of options from airlines and OTAs.

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

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Aer Lingus