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Cheap flights from Seattle to Cardiff from $403

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Cardiff departing on 9/2. 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
7:10 pm - 9:20 pmSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
18h 10m1 stop Dublin
Multiple Airlines Logo
11:35 am - 9:40 amCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
30h 05m2 stops Toronto Pearson Intl Calgary
$1,084Multiple Airlines
Sat, Sep 5 - Sat, Sep 12
Delta Logo
7:15 am - 9:15 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
18h 00m2 stops Chicago O'Hare Intl Amsterdam Schiphol
Delta Logo
9:45 am - 4:35 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
14h 50m1 stop Amsterdam Schiphol
$1,199Delta
Tue, Sep 1 - Tue, Sep 8
Delta Logo
7:15 am - 9:15 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
18h 00m2 stops Chicago O'Hare Intl Amsterdam Schiphol
Delta Logo
9:45 am - 11:55 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
22h 10m2 stops Amsterdam Schiphol Minneapolis St Paul
$1,209Delta
Tue, Sep 1 - Tue, Sep 8
Delta Logo
7:15 am - 9:15 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
18h 00m2 stops Chicago O'Hare Intl Amsterdam Schiphol
Delta Logo
9:45 am - 10:03 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
20h 18m2 stops Amsterdam Schiphol Boston Logan Intl
$1,219Delta
Sat, Sep 5 - Sat, Sep 12
Delta Logo
3:59 pm - 9:15 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
33h 16m2 stops Boston Logan Intl Amsterdam Schiphol
Delta Logo
9:45 am - 4:35 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
14h 50m1 stop Amsterdam Schiphol
$1,225Delta
Fri, Sep 4 - Sat, Sep 12
Delta Logo
3:59 pm - 9:15 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
33h 16m2 stops Boston Logan Intl Amsterdam Schiphol
Delta Logo
9:45 am - 11:20 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
21h 35m2 stops Amsterdam Schiphol New York John F Kennedy Intl
$1,229Delta
Fri, Sep 4 - Sat, Sep 12
Delta Logo
5:45 pm - 9:15 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
31h 30m1 stop Amsterdam Schiphol
Delta Logo
9:45 am - 4:35 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
14h 50m1 stop Amsterdam Schiphol
$1,236Delta
Fri, Sep 4 - Fri, Sep 11
Multiple Airlines Logo
7:10 pm - 6:55 amSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
27h 45m1 stop Dublin
Multiple Airlines Logo
10:50 pm - 6:45 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
27h 55m2 stops Dublin Calgary
$1,242Multiple Airlines
Thu, Aug 20 - Thu, Aug 27
Air France Logo
1:50 pm - 5:05 pmSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
19h 15m1 stop Amsterdam Schiphol
Air France Logo
9:45 am - 4:27 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
14h 42m1 stop Amsterdam Schiphol
$1,244Air France
Fri, Aug 21 - Fri, Aug 28
Delta Logo
1:50 pm - 4:45 pmSEA  Seattle/Tacoma Intl-CWL Cardiff Wales
18h 55m1 stop Amsterdam Schiphol
Delta Logo
9:45 am - 4:27 pmCWL  Cardiff Wales-SEA Seattle/Tacoma Intl
14h 42m1 stop Amsterdam Schiphol
$1,245Delta
Thu, Aug 20 - Thu, Aug 27

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Delta flights from Seattle to Cardiff

Our best Delta deals on Seattle to Cardiff flight tickets
Delta
Sep 1
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Sep 8
CWL9:45 amCardiff Wales
14h 50m
1 stop
SEA4:35 pmSeattle/Tacoma Intl
$1,199
Delta
Sep 1
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Sep 8
CWL9:45 amCardiff Wales
22h 10m
2 stops
SEA11:55 pmSeattle/Tacoma Intl
$1,209
Delta
Aug 10
SEA5:45 pmSeattle/Tacoma Intl
15h 00m
1 stop
CWL4:45 pmCardiff Wales
Aug 17
CWL9:45 amCardiff Wales
33h 52m
1 stop
SEA11:37 amSeattle/Tacoma Intl
$1,215

KLM flights from Seattle to Cardiff

Our best KLM deals on Seattle to Cardiff flight tickets
KLM
Aug 10
SEA5:45 pmSeattle/Tacoma Intl
31h 30m
1 stop
CWL9:15 amCardiff Wales
Aug 17
CWL5:15 pmCardiff Wales
31h 12m
1 stop
SEA4:27 pmSeattle/Tacoma Intl
$1,271
KLM
Sep 1
SEA1:50 pmSeattle/Tacoma Intl
18h 55m
1 stop
CWL4:45 pmCardiff Wales
Sep 8
CWL9:45 amCardiff Wales
14h 50m
1 stop
SEA4:35 pmSeattle/Tacoma Intl
$1,322
KLM
Sep 5
SEA1:50 pmSeattle/Tacoma Intl
18h 55m
1 stop
CWL4:45 pmCardiff Wales
Sep 12
CWL9:45 amCardiff Wales
14h 50m
1 stop
SEA4:35 pmSeattle/Tacoma Intl
$1,724

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 August 9, 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 Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Sat 9/5

7:10 pm-9:20 pm

1 stop18h 10m

Cardiff Wales

Sat 9/12

11:35 am-9:40 am

2 stops30h 05m

$1,084
Quickest round-trip

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Tue 9/1

7:15 am-9:15 am

2 stops18h 00m

Cardiff Wales

Tue 9/8

9:45 am-4:35 pm

1 stop14h 50m

$1,199

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Tue 9/1

7:15 am-9:15 am

2 stops18h 00m

Cardiff Wales

Tue 9/8

9:45 am-11:55 pm

2 stops22h 10m

$1,209

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Sat 9/5

7:15 am-9:15 am

2 stops18h 00m

Cardiff Wales

Sat 9/12

9:45 am-10:03 pm

2 stops20h 18m

$1,219

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Fri 9/4

3:59 pm-9:15 am

2 stops33h 16m

Cardiff Wales

Sat 9/12

9:45 am-4:35 pm

1 stop14h 50m

$1,225

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Fri 9/4

3:59 pm-9:15 am

2 stops33h 16m

Cardiff Wales

Sat 9/12

9:45 am-11:20 pm

2 stops21h 35m

$1,229

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Fri 9/4

5:45 pm-9:15 am

1 stop31h 30m

Cardiff Wales

Fri 9/11

9:45 am-4:35 pm

1 stop14h 50m

$1,236

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Thu 8/20

7:10 pm-6:55 am

1 stop27h 45m

Cardiff Wales

Thu 8/27

10:50 pm-6:45 pm

2 stops27h 55m

$1,242

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Fri 8/21

1:50 pm-5:05 pm

1 stop19h 15m

Cardiff Wales

Fri 8/28

9:45 am-4:27 pm

1 stop14h 42m

$1,244

SeattleCardiff

SEA Seattle/Tacoma Intl - CWL Cardiff Wales

SEACWL

Seattle/Tacoma Intl

Thu 8/20

1:50 pm-4:45 pm

1 stop18h 55m

Cardiff Wales

Thu 8/27

9:45 am-4:27 pm

1 stop14h 42m

$1,245

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 13 resultsSorted by cheapest first
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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 is the cheapest airline that flies from Seattle/Tacoma Intl to Cardiff Wales?

Delta is the most popular carrier operating from Seattle/Tacoma Intl to Cardiff Wales

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

18h 00m

Direct flights

None
The fastest flight from Seattle to Cardiff takes 18h 00m
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 18h 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.

Traveling to a place near Cardiff?

Book flights to Cardiff if you plan to visit one of these locations
Bridgend

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.
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Cabin classes currently available on flights to Cardiff

List of cabin classes available on flights landing in Cardiff. Availability may vary depending on flight origin and airline.
First Class to Cardiff
Business Class to Cardiff