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Cheap flights from St. Louis to Belfast from $1,143

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Belfast departing on 11/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Find the cheapest flights from St. Louis to Belfast

Cheap round-trip flights

Enter your travel dates to find the best prices.
British Airways Logo
7:24 am - 10:20 amSTL  Lambert-St Louis-BHD Belfast City
20h 56m2 stops Chicago O'Hare Intl London Heathrow
British Airways Logo
11:25 am - 11:59 pmBHD  Belfast City-STL Lambert-St Louis
18h 34m2 stops London Heathrow Chicago O'Hare Intl
$1,143British Airways
Sun, Nov 15 - Tue, Nov 17
British Airways Logo
6:00 am - 10:20 amSTL  Lambert-St Louis-BHD Belfast City
22h 20m2 stops Chicago O'Hare Intl London Heathrow
British Airways Logo
11:25 am - 10:15 pmBHD  Belfast City-STL Lambert-St Louis
16h 50m2 stops London Heathrow Chicago O'Hare Intl
$1,143British Airways
Sun, Dec 6 - Tue, Dec 8
British Airways Logo
11:31 am - 10:20 amSTL  Lambert-St Louis-BHD Belfast City
16h 49m2 stops Chicago O'Hare Intl London Heathrow
British Airways Logo
7:25 pm - 4:43 pmBHD  Belfast City-STL Lambert-St Louis
27h 18m2 stops London Heathrow Chicago O'Hare Intl
$1,143British Airways
Sun, Dec 6 - Tue, Dec 8
British Airways Logo
9:50 am - 10:20 amSTL  Lambert-St Louis-BHD Belfast City
18h 30m2 stops Boston Logan Intl London Heathrow
British Airways Logo
11:25 am - 11:59 pmBHD  Belfast City-STL Lambert-St Louis
18h 34m2 stops London Heathrow Chicago O'Hare Intl
$1,143British Airways
Sun, Nov 15 - Tue, Nov 17
British Airways Logo
7:26 am - 10:45 amSTL  Lambert-St Louis-BHD Belfast City
21h 19m2 stops Chicago O'Hare Intl London Heathrow
British Airways Logo
11:40 am - 11:59 pmBHD  Belfast City-STL Lambert-St Louis
18h 19m2 stops London Heathrow Chicago O'Hare Intl
$1,152British Airways
Sun, Dec 6 - Tue, Dec 8
British Airways Logo
7:24 am - 10:45 amSTL  Lambert-St Louis-BHD Belfast City
21h 21m2 stops Chicago O'Hare Intl London Heathrow
British Airways Logo
11:40 am - 11:59 pmBHD  Belfast City-STL Lambert-St Louis
18h 19m2 stops London Heathrow Chicago O'Hare Intl
$1,152British Airways
Sun, Nov 15 - Tue, Nov 17
Multiple Airlines Logo
8:55 am - 10:50 pmSTL  Lambert-St Louis-BFS Belfast Intl
31h 55m3 stops Toronto Pearson Intl Frankfurt am Main Birmingham
Multiple Airlines Logo
10:45 pm - 2:00 pmBFS  Belfast Intl-STL Lambert-St Louis
21h 15m2 stops Manchester Toronto Pearson Intl
$1,308Multiple Airlines
Thu, Sep 24 - Thu, Oct 1
Multiple Airlines Logo
8:55 am - 11:05 pmSTL  Lambert-St Louis-BFS Belfast Intl
32h 10m3 stops Toronto Pearson Intl Frankfurt am Main Birmingham
Multiple Airlines Logo
3:20 pm - 1:25 pmBFS  Belfast Intl-STL Lambert-St Louis
28h 05m2 stops Birmingham Frankfurt am Main
$2,165Multiple Airlines
Sat, Sep 26 - Sat, Oct 3
Multiple Airlines Logo
12:10 pm - 12:25 pmSTL  Lambert-St Louis-BFS Belfast Intl
18h 15m2 stops Montreal Pierre Elliott Trudeau Intl Barcelona-El Prat
Multiple Airlines Logo
3:20 pm - 1:25 pmBFS  Belfast Intl-STL Lambert-St Louis
28h 05m2 stops Birmingham Frankfurt am Main
$2,338Multiple Airlines
Sat, Sep 26 - Sat, Oct 3

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British Airways flights from St. Louis to Belfast

Our best British Airways deals on St. Louis to Belfast flight tickets
British Airways
Nov 15
STL9:50 amLambert-St Louis
18h 30m
2 stops
BHD10:20 amBelfast City
Nov 17
BHD11:25 amBelfast City
18h 34m
2 stops
STL11:59 pmLambert-St Louis
$1,143
British Airways
Nov 15
STL7:24 amLambert-St Louis
21h 21m
2 stops
BHD10:45 amBelfast City
Nov 17
BHD11:40 amBelfast City
18h 19m
2 stops
STL11:59 pmLambert-St Louis
$1,152

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Belfast 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, momondo users made 832,500 searches. Data last updated August 12, 2026.
Use the filters below to find and compare flights from St. Louis to Belfast that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisBelfast

STL Lambert-St Louis - BHD Belfast City

STLBHD

Lambert-St Louis

Sun 11/15

7:24 am-10:20 am

2 stops20h 56m

Belfast City

Tue 11/17

11:25 am-11:59 pm

2 stops18h 34m

$1,143

St. LouisBelfast

STL Lambert-St Louis - BHD Belfast City

STLBHD

Lambert-St Louis

Sun 12/6

6:00 am-10:20 am

2 stops22h 20m

Belfast City

Tue 12/8

11:25 am-10:15 pm

2 stops16h 50m

$1,143

St. LouisBelfast

STL Lambert-St Louis - BHD Belfast City

STLBHD

Lambert-St Louis

Sun 12/6

11:31 am-10:20 am

2 stops16h 49m

Belfast City

Tue 12/8

7:25 pm-4:43 pm

2 stops27h 18m

$1,143
Quickest round-trip

St. LouisBelfast

STL Lambert-St Louis - BHD Belfast City

STLBHD

Lambert-St Louis

Sun 11/15

9:50 am-10:20 am

2 stops18h 30m

Belfast City

Tue 11/17

11:25 am-11:59 pm

2 stops18h 34m

$1,143

St. LouisBelfast

STL Lambert-St Louis - BHD Belfast City

STLBHD

Lambert-St Louis

Sun 12/6

7:26 am-10:45 am

2 stops21h 19m

Belfast City

Tue 12/8

11:40 am-11:59 pm

2 stops18h 19m

$1,152

St. LouisBelfast

STL Lambert-St Louis - BHD Belfast City

STLBHD

Lambert-St Louis

Sun 11/15

7:24 am-10:45 am

2 stops21h 21m

Belfast City

Tue 11/17

11:40 am-11:59 pm

2 stops18h 19m

$1,152

St. LouisBelfast

STL Lambert-St Louis - BFS Belfast Intl

STLBFS

Lambert-St Louis

Thu 9/24

8:55 am-10:50 pm

3 stops31h 55m

Belfast Intl

Thu 10/1

10:45 pm-2:00 pm

2 stops21h 15m

$1,308

St. LouisBelfast

STL Lambert-St Louis - BFS Belfast Intl

STLBFS

Lambert-St Louis

Sat 9/26

8:55 am-11:05 pm

3 stops32h 10m

Belfast Intl

Sat 10/3

3:20 pm-1:25 pm

2 stops28h 05m

$2,165

St. LouisBelfast

STL Lambert-St Louis - BFS Belfast Intl

STLBFS

Lambert-St Louis

Sat 9/26

12:10 pm-12:25 pm

2 stops18h 15m

Belfast Intl

Sat 10/3

3:20 pm-1:25 pm

2 stops28h 05m

$2,338

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

Cheap St. Louis to Belfast flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Belfast

Fastest flight time

21h 19m

Direct flights

None
The fastest flight from St. Louis to Belfast takes 21h 19m
There are no direct flights from St. Louis to Belfast. There are no popular flight routes from St. Louis to Belfast.
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Frequently asked questions about flying from St. Louis to Belfast

  • How far is Lambert-St Louis to Belfast by plane?

    The straight-line distance from Lambert-St Louis to Belfast is 3891.1 mi. Flights usually cover this in 21h 19m, depending on flying conditions and air traffic around both airports.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Belfast?

    Prices for flights from Lambert-St Louis Airport to Belfast are refreshed on a daily basis.

  • How old do you have to be to fly from Lambert-St Louis Airport to Belfast?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Belfast.

  • What documentation or ID do you need to fly to Belfast?

    The travel and health documents required for your trip to Belfast can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Belfast. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

Frequently asked questions about flying from St. Louis to Belfast

  • How do I get Price Alerts for flights from St. Louis to Belfast?

    Price Alerts will notify you by email when the price for flights to Belfast from St. Louis decreases. To activate this, select your desired travel dates and search for offers. While browsing through offers you’ll see the Price Alert widget toggle. Click it to turn on notifications.

  • How can I save money on flights from St. Louis to Belfast with momondo?

    By using tools like our “Price Calendar”, you can see the best day to fly round-trip for your travels. Our “Price Forecast” tool uses AI to predict whether you should purchase or hold off on booking for potentially cheaper prices. Explore shows you all flight options from a city or airport to build your own unique adventure. The Discover blog also provides valuable insights for saving money while booking your experience. After searching you can toggle on “Price Alerts” to track prices for your desired flight and book at the ideal moment.

  • How does momondo find its flight prices?

    momondo shows deals across 700+ competitors all at once. momondo is active in 30 international markets, so you can have access to a wide range of options from airlines and OTAs alike.

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Belfast?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Belfast from St. Louis.

Can I find flights from St. Louis to Belfast with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for St. Louis to Belfast flights to just show those with flexible booking policies.

How can momondo help me find flights from St. Louis to Belfast?

Once all potential St. Louis to Belfast flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

I’m not ready to book a flight from St. Louis to Belfast right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to Belfast from St. Louis. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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Find better results for your trip to the United Kingdom

Fly into one of these airports located in Belfast

Airports listed have a maximum distance of 12.2 mi from Belfast
Belfast Intl Airport
Belfast City Airport