£340 Cheap Flights from Washington (IAD) to Cardiff (CWL)

View £340 flight on Mon, 14 Sept 2026Opens in a new window

Flight 1

Popular airlines from Washington Dulles International Airport (IAD) to Cardiff International Airport (CWL)

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Cheap Flights from Washington (IAD) to Cardiff (CWL)

Prices were available within the past 7 days and start at £340 for one-way flights and £826 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Air France
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£826 Return, found 3 days ago
£826
Return
found 3 days ago
Select Air France flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £826 found 3 days ago
Delta
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£826 Return, found 3 days ago
£826
Return
found 3 days ago
Select Delta flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £826 found 3 days ago
KLM
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£826 Return, found 3 days ago
£826
Return
found 3 days ago
Select KLM flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £826 found 3 days ago
Virgin Atlantic
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£826 Return, found 3 days ago
£826
Return
found 3 days ago
Select Virgin Atlantic flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £826 found 3 days ago
Delta
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£847 Return, found 3 days ago
£847
Return
found 3 days ago
Select Delta flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £847 found 3 days ago
Delta
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£851 Return, found 3 days ago
£851
Return
found 3 days ago
Select Delta flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £851 found 3 days ago
KLM
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£868 Return, found 3 days ago
£868
Return
found 3 days ago
Select KLM flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £868 found 3 days ago
Delta
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£869 Return, found 3 days ago
£869
Return
found 3 days ago
Select Delta flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £869 found 3 days ago
KLM
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£872 Return, found 3 days ago
£872
Return
found 3 days ago
Select KLM flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £872 found 3 days ago
Delta
Mon, 14 Sept - Thu, 17 Sept
IAD
Washington
CWL
Cardiff
£890 Return, found 3 days ago
£890
Return
found 3 days ago
Select Delta flight, departing Mon, 14 Sept from Washington to Cardiff, returning Thu, 17 Sept, priced at £890 found 3 days ago

Frequently asked questions

How do I find cheap flights from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
To find a cheap flight from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
How many flights per day from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
There are approximately 13 connecting flights per day from Washington Dulles Intl. (IAD) to Cardiff Intl. (CWL). Some common connection points include Hartsfield-Jackson Atlanta Intl. (ATL), Roissy-Charles de Gaulle (CDG), and Pearson Intl. (YYZ).
What is the earliest flight from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
The earliest flight from Washington Dulles Intl. (IAD) to Cardiff Intl. (CWL) typically departs at approximately 6:00 AM local time. This service is operated by Delta and KLM, and it is a seasonal service active in May. An early departure like this can help you maximise your time at your destination. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What day of the week has the most flights from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
You'll typically find the most flights from Washington Dulles Intl. (IAD) to Cardiff Intl. (CWL) on a Friday, with around 33 flights available. This gives you a good selection of options for your journey. Major airlines on this route include Delta Air Lines, KLM, and British Airways.
What are the most popular departure times for flights from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
The most popular departure times for flights from Washington Dulles Intl. (IAD) to Cardiff Intl. (CWL) are in the afternoon, from 3pm to 6pm. This accounts for around 61% of total traffic. Many major carriers, including Air Canada and KLM, offer flights during this window. This timing works well because it allows you to have a productive morning before heading to the airport, and you'll arrive at your destination in the evening.
How long does it take to fly from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
A flight from IAD to CWL with a layover takes around 10 hours 30 minutes, with the route covering approximately 3,550 miles. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
Select the "Business class" and "First class" filters when looking for IAD to CWL flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
How do I earn miles on a Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) flight with Expedia?
It's easy to earn miles on a Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia. *Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Cardiff from Washington Dulles Intl. (IAD)?
If you're planning to travel to Cardiff from Washington Dulles Intl. (IAD), you can fly directly into Cardiff Intl. (CWL) Some flights may connect through major hubs like Pearson Intl. (YYZ), Pierre Elliott Trudeau Intl. (YUL), Hartsfield-Jackson Atlanta Intl. (ATL) before reaching Cardiff. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) at the last minute?
Typically, booking a last minute flight from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) flight and hotel package?
Securing a Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.)?
If you booked your Washington, DC (IAD-Washington Dulles Intl.) to Cardiff (CWL-Cardiff Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Washington Dulles Intl.
Destination airport
Cardiff Intl.
Return price
£826
Distance
5679 km

Book with confidence

Compare flights from Washington to Cardiff easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from Washington to Cardiff. Operating between them flights per day, 20 airlines cover the route. And fly direct, getting you to Cardiff Intl. in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Washington Dulles Intl. to Cardiff Intl..  

To make things even better, in the advanced search, you can also choose to fly economy, premium economy, business or first class, select your maximum number of stops, and pick your preferred departure and arrival time. You can also opt for refundable and direct flights. 

Grab a great deal on your flight from Washington Dulles Intl. (IAD) to Cardiff Intl. (CWL)

The easiest way to view the best deals on flights from Washington to Cardiff today is to enter your travel dates and hit search. From here, you can sort your results by price to see the cheapest flights first. Right now, return flights from Washington Dulles Intl. to Cardiff Intl. start at just £826 and range up to £890.  

To find an even better deal, try  

  • being flexible on your dates – midweek flights can be cheaper
  • looking for other airports near Washington and Cardiff
  • booking your flight during September, the cheapest month on this route
  • varying your flight times – early morning and late at night are sometimes cheaper 

Why you should book your Washington to Cardiff flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Washington Dulles Intl. to Cardiff Intl. for a budget break or a business trip with a bit of pleasure thrown in, we make it easy to secure the seat that’s right for you.  

Thanks to our supersized inventory that offers great choice all in one place, you know you’ll get a great deal with Expedia. Especially if you bundle your flight together with your hotel, you will unlock amazing savings. For added peace of mind, you can choose flexible bookings or filter to find refundable options, so you won’t pay a fee to change your flight.  

Compare flights from Washington to Cardiff easily and book with confidence

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*Available to Expedia members.