Cheap Flights from Seattle (SEA) to Belfast (BFS)

Popular airlines from Seattle-Tacoma International Airport (SEA) to Belfast International Airport (BFS)

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Frequently asked questions

How much does a flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.) cost?
You can find cheap one-way flights and cheap return flights Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.) with Expedia. One-way flights usually range from $272 to $3458, and return flights typically cost between $1390 and $6696. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
The cheapest month to fly from SEA to BFS is when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you're able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
Enter SEA to BFS and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
Iberia is one of the cheapest airlines offering connecting flights from Seattle, WA (SEA) to Belfast (BFS) with a layover in Dallas-Fort Worth Intl. (DFW), with round-trip tickets starting from around $1,293. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
To find a cheap flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast 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.
What is the earliest flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
The earliest flight from Seattle - Tacoma International Airport (SEA) to Belfast International Airport (BFS) typically departs at around 12:55 AM local time, operated by American Airlines and British Airways. This is a seasonal service active in February, allowing you to start your journey early and make the most of your time in Belfast. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
The most popular departure times for flights from Seattle - Tacoma Intl. (SEA) to Belfast Intl. (BFS) are in the early afternoon, from 12pm to 3pm. About 45% of passengers prefer this time window. Many major carriers, including British Airways and Aer Lingus, offer flights during this window. This timing works well because it allows you to start your journey after a leisurely morning.
Can you fly business or first class from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
You can fly business class between SEA and BFS. Airlines that offer business class service on this route include:

  • British Airways
  • Delta Air Lines
  • American Airlines
  • Air France
  • Finnair

How do I earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.) flight with Expedia?
It's easy to earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast 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 Belfast from Seattle - Tacoma Intl. (SEA)?
From Seattle - Tacoma Intl. (SEA), you can fly into Belfast Intl. (BFS) and George Best Belfast City (BHD) in Belfast. Some flights may connect through major hubs like Dallas-Fort Worth Intl. (DFW), Heathrow (LHR), O'Hare Intl. (ORD) before reaching Belfast. 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.) at the last minute?
Typically, booking a last minute flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.) flight and hotel package?
Securing a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast Intl.)?
If you booked your Seattle, WA (SEA-Seattle - Tacoma Intl.) to Belfast (BFS-Belfast 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
Seattle - Tacoma Intl.
Destination airport
Belfast Intl.
Distance
4463 mi

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Seattle to Belfast Flights

The cheapest times to fly from Seattle to Belfast

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Seattle to Belfast are during the month of . You can find some of the cheapest flights from Seattle to Belfast with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Seattle to Belfast

Sunday is one of the best days to book for cheap flights from Seattle to Belfast: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Seattle to Belfast

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Seattle to Belfast in 2026. You can also book with separate airlines for your outbound and return journeys, from one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Seattle to Belfast flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Seattle to Belfast airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Seattle to Belfast Flights

*Flight schedules are subject to change.

*Available to One Key members.

 

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