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Cheap flights from Belfast to Seattle from £555

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/5. Fares are subject to change and may not be available on all flights or dates of travel.
BHD — SEA
6 May — 13 May1
1 adult

Cheap flight deals from Belfast to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Belfast (BF1) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 1 May 2025.

Round-trip from

£600

Popular in

July

Cheapest in

May

Average price

£438
KLM
  • KLM
  • 21/5-30/5
  • 2 total stops
  • 40h 47m total
  • Belfast to Seattle
Search Deals
Highest demand for flights based on searches. 18% potential increase in price (£110 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£17 potential savings vs. average return price).
Search Deals
Average for round-trip flights in May 2025
Search Deals

Find flight deals from Belfast to Seattle

Cheapest flights from Belfast to Seattle
Explore the most affordable flight options available from Belfast to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 1 May 2025.

Thu 8/517:25BHD - SEA
1 stop30h 32mKLM
Thu 22/518:07SEA - BHD
1 stop19h 08mKLM
Deal found 30/4£555
Thu 8/506:35BHD - SEA
1 stop19h 45mBritish Airways
Thu 22/513:30SEA - BHD
1 stop15h 45mBritish Airways
Deal found 1/5£557
Thu 8/519:25BHD - SEA
1 stop24h 10mMultiple Airlines
Thu 22/513:30SEA - BHD
1 stop13h 40mMultiple Airlines
Deal found 30/4£573
Thu 8/506:30BHD - SEA
2 stops19h 20mDelta
Thu 22/518:07SEA - BHD
1 stop19h 08mDelta
Deal found 30/4£602
Thu 8/506:35BHD - SEA
1 stop13h 00mAmerican Airlines
Thu 22/513:30SEA - BHD
1 stop15h 45mAmerican Airlines
Deal found 30/4£613
Tue 8/722:55BFS - SEA
3 stops31h 21mMultiple Airlines
Mon 8/915:45SEA - BFS
2 stops16h 05mMultiple Airlines
Deal found 30/4£650

Cheapflights Fare Finder

Customise your flight search to find flights from Belfast to Seattle 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 1 May 2025.
Use the filters below to find and compare flights from Belfast to Seattle that are best for you.

Fly from

Belfast

Fly to

Seattle

Route

Depart

Return

Price

BelfastSeattle

BHD - SEA

BHDSEA

Belfast City

Wed 21/5

06:30-15:57

1 stop17h 27m

Seattle/Tacoma Intl

Fri 30/5

13:55-21:15

1 stop23h 20m

£600

BelfastSeattle

BFS - SEA

BFSSEA

Belfast Intl

Tue 8/7

22:55-22:16

3 stops31h 21m

Seattle/Tacoma Intl

Mon 8/9

15:45-15:50

2 stops16h 05m

£650

BelfastSeattle

BHD - SEA

BHDSEA

Belfast City

Wed 21/5

11:30-22:47

2 stops19h 17m

Seattle/Tacoma Intl

Fri 30/5

16:00-18:15

2 stops18h 15m

£711

BelfastSeattle

BHD - SEA

BHDSEA

Belfast City

Wed 30/7

10:00-21:43

2 stops19h 43m

£819

BelfastSeattle

BHD - SEA

BHDSEA

Belfast City

Wed 30/7

20:15-11:35

1 stop23h 20m

£830

Flights are sorted by cheapest return flights first.

Deals found on 30/4

Best time to book a flight from Belfast to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Belfast 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 Belfast to Seattle

What is the cheapest time of day to fly from BFS to SEA?

Find hourly flight availability from Belfast to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 1 May 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Belfast to Seattle as you normally would.

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 inches per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated 1 May 2025.
Peruse reviews from past customers who have flown with KLM and British Airways from Belfast to Seattle to help guide your decision. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
KLM
7.8
Good
1,334 reviews
Check prices

Boarding

7.8

Comfort

7.7

Crew

8.4

Overall

7.8

Food

7.2

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Mar 2025

LBA - AMS

Overall, the flight from Leeds Bradford to Amsterdam was at expected. The crew were efficient at boarding and professional on board. The only issue was extremely slow check in at Leeds Bradford which was very frustrating.
KLM
7.8
Good
1,334 reviews
KLM
7.8
Good
1,334 reviews
Check prices

Boarding

7.8

Comfort

7.7

Crew

8.4

Overall

7.8

Food

7.2

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Mar 2025

LBA - AMS

Overall, the flight from Leeds Bradford to Amsterdam was at expected. The crew were efficient at boarding and professional on board. The only issue was extremely slow check in at Leeds Bradford which was very frustrating.
British Airways
6.6
Okay
6,845 reviews
KLM
7.8
Good
1,334 reviews
Check prices

Boarding

7.8

Comfort

7.7

Crew

8.4

Overall

7.8

Food

7.2

Entertainment

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Mar 2025

LBA - AMS

Overall, the flight from Leeds Bradford to Amsterdam was at expected. The crew were efficient at boarding and professional on board. The only issue was extremely slow check in at Leeds Bradford which was very frustrating.

Related info for your journey

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

  • What airport do you fly into for flights to Seattle from Belfast?

    Most people fly into Seattle/Tacoma Intl (SEA) if they book a flight to Seattle from Belfast. On average, Seattle/Tacoma Intl has 0 inbound flights from Belfast per day from 1 airline. Seattle/Tacoma Intl is conveniently located just 11.4 mi from Seattle’s city center.

  • What are the cheapest airlines flying from Belfast to Seattle round-trip?

    KLM, at £600, was found to be the cheapest airline from Belfast to Seattle. An alternate airline flying to your destination would be British Airways. KLM is priced at 4% lower than the current average price of a flight leaving 3 months from now.

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

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

  • How can I find direct flights from Belfast to Seattle?

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

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

    Yes. Cheapflights offers flight deals from Belfast to Seattle 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 Belfast to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Belfast to Seattle (average of £622). Flying from Belfast to Seattle in July is currently the most expensive (average of £946). 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?

Book flights to Belfast if you plan to visit one of these locations
Tacoma
Leavenworth
Bothell

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Belfast to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
Belfast Intl to Seattle flights
Belfast City to Seattle flights

Top airline flying from Belfast to Seattle

Discover the top airline that operate flights from Belfast to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 858,174 searches. Data last updated 1 May 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest£440Average£526FlexibilityNo cancel feeOn-time70%
Search British Airways flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Belfast to Seattle?

Cheapflights goes through 900+ travel sites to look for the best flight deals for flights from Belfast to Seattle. Too many options? Cheapflights also provides filters for things like airlines, price ranges, and number of stops to help you make a decision easily.

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

Millions of users choose and trust Cheapflights to book the best flight deals from Belfast to Seattle for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

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

Certainly. Search results for flights to Seattle from Belfast shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on Belfast to Seattle 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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