£395 Cheap Flights from Seattle (SEA) to Londonderry (LDY)

View £395 flight on Sun, 2 Aug 2026Opens in a new window

Popular airlines from Seattle-Tacoma International Airport (SEA) to Londonderry (LDY-City of Derry)

Cheap Flights from Seattle (SEA) to Londonderry (LDY)

Prices were available within the past 7 days and start at £395 for one-way flights and for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frequently asked questions

How do I find cheap flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
To find a cheap flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry), 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
There are approximately 8 connecting flights per day from Seattle - Tacoma Intl. (SEA) to City of Derry (LDY). Some common connection points include Unknown (DUB), Heathrow (LHR), and San Francisco Intl. (SFO).
What is the earliest flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
Sort flights by "Departure (earliest)" on Expedia to find the earliest flight from SEA to LDY. To compare more early flights, use the "Early Morning" and "Morning" filters in your search.
How long does it take to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
Flights from SEA to LDY with one stop typically take around 14 hours 50 minutes, covering approximately 4,419 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
Select the "Business class" and "First class" filters when looking for SEA to LDY 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) flight with Expedia?
It's easy to earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) 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.
Is it cheaper to buy a plane ticket from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) at the last minute?
Typically, booking a last minute flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) flight and hotel package?
Securing a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry)?
If you booked your Seattle, WA (SEA-Seattle - Tacoma Intl.) to Londonderry (LDY-City of Derry) 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
Seattle - Tacoma Intl.
Destination airport
City of Derry
Distance
7069 km

Book with confidence

Compare flights from Seattle to Londonderry easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from Seattle to Londonderry. Operating between them flights per day, 19 airlines cover the route. And fly direct, getting you to City of Derry in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Seattle - Tacoma Intl. to City of Derry.  

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 Seattle - Tacoma Intl. (SEA) to City of Derry (LDY)

The easiest way to view the best deals on flights from Seattle to Londonderry 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 Seattle - Tacoma Intl. to City of Derry start at just and range up to .  

To find an even better deal, try  

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

Why you should book your Seattle to Londonderry flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Seattle - Tacoma Intl. to City of Derry 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 Seattle to Londonderry easily and book with confidence

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*Available to Expedia members.