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Cheap flights from Washington to Belfast Intl Airport from £532

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 13/10. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BFS
16 Oct — 23 Oct1
1 adult
1 adult, Economy

Cheap flight deals from Washington to Belfast Intl

Keep the following information in mind while searching for Washington to Belfast Intl flight deals. Data was last updated 16 September 2025.

Round-trip from

£532

Popular in

December

Cheapest in

March

Average price

£725
13/10-20/10
  • 13/10-20/10
  • 4 total stops
  • 43h 10m total
  • Washington to Belfast
Search Deals
Highest demand for flights based on searches. 7% potential increase in price (£39 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£16 potential savings vs. average return price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

Find flight deals from Washington to Belfast Intl

Cheapest flights from Washington to Belfast Intl
Explore the most affordable flight options available from Washington to Belfast Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 16 September 2025.

Mon 13/1015:45SEA - BFS
2 stops20h 40mMultiple Airlines
Mon 20/1006:10BFS - SEA
2 stops22h 30mMultiple Airlines
Deal found 15/9£532
Wed 1/1019:00SEA - BFS
2 stops17h 35mMultiple Airlines
Wed 8/1006:10BFS - SEA
2 stops22h 30mMultiple Airlines
Deal found 14/9£567

Cheapflights Fare Finder

 
Customise your flight search to find flights from Washington to Belfast Intl 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, Cheapflights users made 858,174 searches. Data last updated 16 September 2025.
Use the filters below to find and compare flights from Washington to Belfast Intl Airport that are best for you.

Fly from

Washington

Fly to

Belfast Intl

Route

Depart

Return

Price

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Mon 13/10

15:45-20:25

2 stops20h 40m

Belfast Intl

Mon 20/10

06:10-20:40

2 stops22h 30m

£532

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Wed 1/10

19:00-20:35

2 stops17h 35m

Belfast Intl

Wed 8/10

06:10-20:40

2 stops22h 30m

£567

Flights are sorted by cheapest return flights first.

Deals found on 15/9

Best time to book a flight from Washington to Belfast Intl

Have a flexible travel schedule? Discover the best time to fly to Belfast Intl from Washington with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington to Belfast Intl Airport
No data available for this route at this time. Please check back soon.

Related info for your journey

Find useful and relevant information for your journey from Washington to Belfast Intl. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • Can I find deals for flights from Washington to Belfast Intl that include hotel bookings?

    Yes. In addition to deals on Washington to Belfast Intl flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Washington to Belfast Intl?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Washington to Belfast Intl.

  • Can I find deals for business class flights from Washington to Belfast Intl?

    Yes. Cheapflights offers flight deals from Washington to Belfast Intl by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from State of Washington to Belfast Intl Airport?

    Currently, January is the cheapest month in which you can book a flight from State of Washington to Belfast Intl Airport (average of £67). Flying from State of Washington to Belfast Intl Airport in July is currently the most expensive (average of £90). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near Belfast Intl Airport?

Book flights to Belfast Intl Airport if you plan to visit one of these locations
Armagh
Newry
Ballymena
Cookstown
Dungannon

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Alternative routes for Washington to Belfast Intl

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Yes, Cheapflights offers price alerts on Washington to Belfast Intl flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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