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Cheap flights from Seattle to Cardiff from $346

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 6/30. 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
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 - 10:50 pm
SEA
-
CWL
19h 40m
1 stop
Multiple Airlines Logo
10:10 pm - 6:45 pm
CWL
-
SEA
28h 35m
2 stops
$997Multiple Airlines
Mon, Aug 10 - Mon, Aug 17
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
2 stops
Multiple Airlines Logo
10:10 pm - 9:00 pm
CWL
-
SEA
30h 50m
3 stops
$1,019Multiple Airlines
Thu, Aug 13 - Mon, Aug 17
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
3 stops
Multiple Airlines Logo
10:10 pm - 9:00 pm
CWL
-
SEA
30h 50m
3 stops
$1,022Multiple Airlines
Thu, Aug 13 - Mon, Aug 17
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
2 stops
Multiple Airlines Logo
11:15 pm - 9:00 pm
CWL
-
SEA
29h 45m
3 stops
$1,023Multiple Airlines
Thu, Aug 13 - Tue, Aug 18
Multiple Airlines Logo
7:35 pm - 10:15 am
SEA
-
CWL
30h 40m
3 stops
Multiple Airlines Logo
11:15 pm - 9:00 pm
CWL
-
SEA
29h 45m
3 stops
$1,025Multiple Airlines
Thu, Aug 13 - Tue, Aug 18
Multiple Airlines Logo
7:10 pm - 10:20 pm
SEA
-
CWL
19h 10m
1 stop
Multiple Airlines Logo
11:35 am - 9:40 am
CWL
-
SEA
30h 05m
2 stops
$1,041Multiple Airlines
Thu, Aug 13 - Tue, Aug 18
Multiple Airlines Logo
7:10 pm - 10:20 pm
SEA
-
CWL
19h 10m
1 stop
Multiple Airlines Logo
10:10 pm - 6:45 pm
CWL
-
SEA
28h 35m
2 stops
$1,043Multiple Airlines
Thu, Aug 13 - Mon, Aug 17
Virgin Atlantic Logo
7:15 am - 9:15 am
SEA
-
CWL
18h 00m
2 stops
Virgin Atlantic Logo
5:15 pm - 10:05 pm
CWL
-
SEA
36h 50m
2 stops
$1,077Virgin Atlantic
Mon, Aug 10 - Mon, Aug 17
KLM Logo
5:45 pm - 4:45 pm
SEA
-
CWL
15h 00m
1 stop
KLM Logo
9:45 am - 11:37 am
CWL
-
SEA
33h 52m
1 stop
$1,093KLM
Thu, Aug 13 - Tue, Aug 18
KLM Logo
7:20 am - 9:15 am
SEA
-
CWL
17h 55m
2 stops
KLM Logo
5:15 pm - 11:37 am
CWL
-
SEA
26h 22m
1 stop
$1,095KLM
Mon, Aug 10 - Mon, Aug 17

Virgin Atlantic flights from Seattle to Cardiff

Our best Virgin Atlantic deals on Seattle to Cardiff flight tickets
Virgin Atlantic
Aug 10
SEA7:15 amSeattle/Tacoma Intl
18h 00m
2 stops
CWL9:15 amCardiff Wales
Aug 17
CWL5:15 pmCardiff Wales
36h 50m
2 stops
SEA10:05 pmSeattle/Tacoma Intl
$1,077
Virgin Atlantic
Aug 10
SEA1:50 pmSeattle/Tacoma Intl
18h 55m
1 stop
CWL4:45 pmCardiff Wales
Aug 17
CWL5:15 pmCardiff Wales
26h 22m
1 stop
SEA11:37 amSeattle/Tacoma Intl
$1,179

KLM flights from Seattle to Cardiff

Our best KLM deals on Seattle to Cardiff flight tickets
KLM
Aug 13
SEA5:45 pmSeattle/Tacoma Intl
15h 00m
1 stop
CWL4:45 pmCardiff Wales
Aug 18
CWL9:45 amCardiff Wales
33h 52m
1 stop
SEA11:37 amSeattle/Tacoma Intl
$1,093
KLM
Aug 10
SEA7:20 amSeattle/Tacoma Intl
17h 55m
2 stops
CWL9:15 amCardiff Wales
Aug 17
CWL5:15 pmCardiff Wales
26h 22m
1 stop
SEA11:37 amSeattle/Tacoma Intl
$1,095
KLM
Aug 13
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
$1,110

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 May 5, 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

Mon 8/10

7:10 pm-10:50 pm

1 stop19h 40m

Cardiff Wales

Mon 8/17

10:10 pm-6:45 pm

2 stops28h 35m

$997

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

7:35 pm-10:15 am

2 stops30h 40m

Cardiff Wales

Mon 8/17

10:10 pm-9:00 pm

3 stops30h 50m

$1,019

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

7:35 pm-10:15 am

3 stops30h 40m

Cardiff Wales

Mon 8/17

10:10 pm-9:00 pm

3 stops30h 50m

$1,022

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

7:35 pm-10:15 am

2 stops30h 40m

Cardiff Wales

Tue 8/18

11:15 pm-9:00 pm

3 stops29h 45m

$1,023

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

7:35 pm-10:15 am

3 stops30h 40m

Cardiff Wales

Tue 8/18

11:15 pm-9:00 pm

3 stops29h 45m

$1,025

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

7:10 pm-10:20 pm

1 stop19h 10m

Cardiff Wales

Tue 8/18

11:35 am-9:40 am

2 stops30h 05m

$1,041

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

7:10 pm-10:20 pm

1 stop19h 10m

Cardiff Wales

Mon 8/17

10:10 pm-6:45 pm

2 stops28h 35m

$1,043

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/10

7:15 am-9:15 am

2 stops18h 00m

Cardiff Wales

Mon 8/17

5:15 pm-10:05 pm

2 stops36h 50m

$1,077

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Thu 8/13

5:45 pm-4:45 pm

1 stop15h 00m

Cardiff Wales

Tue 8/18

9:45 am-11:37 am

1 stop33h 52m

$1,093
Quickest round-trip

SeattleCardiff

SEA - CWL

SEACWL

Seattle/Tacoma Intl

Mon 8/10

7:20 am-9:15 am

2 stops17h 55m

Cardiff Wales

Mon 8/17

5:15 pm-11:37 am

1 stop26h 22m

$1,095

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 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?

WestJet 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 55m

Direct flights

None
The fastest flight from Seattle to Cardiff takes 18h 55m
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 55m.

  • 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.
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Thu 6/4
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Aer Lingus