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Cheap flights from Washington to Belfast Intl Airport from £326

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 28/5. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BFS
28 Feb — 7 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Washington to Belfast Intl

Enter your travel dates to find the best prices.

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 29 January 2026.

Mon 9/319:50
SEA
-
BFS
2 stops16h 15m
Multiple Airlines
Sun 15/322:10
BFS
-
SEA
2 stops45h 20m
Multiple Airlines
Deal found 28/1£528
Fri 13/316:10
SEA
-
BFS
3 stops23h 35m
Multiple Airlines
Fri 20/307:50
BFS
-
SEA
3 stops41h 15m
Multiple Airlines
Deal found 27/1£941
Fri 13/314:25
PDX
-
BFS
2 stops17h 45m
Multiple Airlines
Fri 20/306:30
BFS
-
PDX
2 stops18h 30m
Multiple Airlines
Deal found 27/1£1,007

Find 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 29 January 2026.

Round-trip from

£528

One-way from

£326

Popular in

December

Cheapest in

April

Average price

£689
9/3-15/3
  • 9/3-15/3
  • 4 total stops
  • 61h 35m total
  • Washington to Belfast
Search Deals
28/5
  • 28/5
  • 2 total stops
  • 38h 25m total
  • Washington to Belfast
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (£64 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease (£32 potential savings vs. average return price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

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 29 January 2026.
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 9/3

19:50-19:05

2 stops16h 15m

Belfast Intl

Sun 15/3

22:10-12:30

2 stops45h 20m

£528

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Fri 13/3

15:00-18:55

2 stops20h 55m

Belfast Intl

Fri 20/3

11:45-13:10

2 stops32h 25m

£976

PortlandBelfast

PDX - BFS

PDXBFS

Portland

Fri 13/3

14:25-15:10

2 stops17h 45m

Belfast Intl

Fri 20/3

06:30-18:00

2 stops18h 30m

£1,007

SeattleBelfast

SEA - BFS

SEABFS

Seattle/Tacoma Intl

Thu 28/5

23:25-21:50

2 stops38h 25m

£326

Flights are sorted by cheapest return flights first.

Deals found on 26/1

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

How much does it cost for a return flight from State of Washington to Belfast Intl Airport?

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.

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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Fly with Cheapflights

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How does Cheapflights help users find flights from Washington to Belfast Intl?

Deals for Washington to Belfast Intl flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Washington to Belfast Intl?

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Can Cheapflights find flights from Washington to Belfast Intl with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Washington to Belfast Intl flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Washington to Belfast Intl become cheaper?

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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