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Cheap flights from St. Louis to Belfast from $5,433

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 8/25. 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
0 bags

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Find the cheapest flights from St. Louis to Belfast

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
8:55 am - 5:45 pm
STL
-
BHD
26h 50m
2 stops
Multiple Airlines Logo
9:35 am - 11:51 pm
BHD
-
STL
20h 16m
2 stops
$5,433Multiple Airlines
Tue, Aug 25 - Sat, Aug 29
Multiple Airlines Logo
9:35 pm - 6:55 pm
STL
-
BHD
15h 20m
1 stop
Multiple Airlines Logo
12:40 pm - 8:02 pm
BHD
-
STL
37h 22m
2 stops
$5,457Multiple Airlines
Tue, Aug 25 - Sat, Aug 29
Aer Lingus Logo
9:35 pm - 3:20 pm
STL
-
BHD
11h 45m
1 stop
Aer Lingus Logo
4:15 pm - 7:30 pm
BHD
-
STL
33h 15m
1 stop
$5,514Aer Lingus
Tue, Aug 25 - Sat, Aug 29
Multiple Airlines Logo
6:15 pm - 8:05 pm
STL
-
BHD
19h 50m
3 stops
Multiple Airlines Logo
7:05 am - 7:14 pm
BHD
-
STL
18h 09m
2 stops
$6,058Multiple Airlines
Tue, Aug 25 - Sat, Aug 29

British Airways flights from St. Louis to Belfast

Our best British Airways deals on St. Louis to Belfast flight tickets
British Airways
Mar 4
STL2:00 pmLambert-St Louis
14h 15m
2 stops
BHD10:15 amBelfast City
Mar 8
BHD6:30 amBelfast City
22h 14m
2 stops
STL10:44 pmLambert-St Louis
$1,107
British Airways
Mar 5
STL6:00 amLambert-St Louis
32h 30m
2 stops
BHD8:30 pmBelfast City
Mar 9
BHD5:45 pmBelfast City
34h 59m
2 stops
STL11:44 pmLambert-St Louis
$1,170
British Airways
Mar 5
STL6:00 amLambert-St Louis
32h 30m
2 stops
BHD8:30 pmBelfast City
Mar 9
BHD7:25 pmBelfast City
32h 37m
2 stops
STL11:02 pmLambert-St Louis
$1,176

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 March 2, 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

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Tue 8/25

8:55 am-5:45 pm

2 stops26h 50m

Belfast City

Sat 8/29

9:35 am-11:51 pm

2 stops20h 16m

$5,433

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Tue 8/25

9:35 pm-6:55 pm

1 stop15h 20m

Belfast City

Sat 8/29

12:40 pm-8:02 pm

2 stops37h 22m

$5,457

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Tue 8/25

9:35 pm-3:20 pm

1 stop11h 45m

Belfast City

Sat 8/29

4:15 pm-7:30 pm

1 stop33h 15m

$5,514

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Tue 8/25

6:15 pm-8:05 pm

3 stops19h 50m

Belfast City

Sat 8/29

7:05 am-7:14 pm

2 stops18h 09m

$6,058

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

14h 15m

Direct flights

None
The fastest flight from St. Louis to Belfast takes 14h 15m
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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  • 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 14h 15m, 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.

  • 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