Cheap flights from St. Louis to Belfast from $583

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 9/29. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Cheap round-trip flights

Multiple Airlines Logo
1:26 pm - 11:10 pmSTL-BFS
27h 44m2 stops
Multiple Airlines Logo
6:45 am - 10:04 pmBFS-STL
21h 19m2 stops
$583Multiple Airlines
Find Deal
Mon, Sep 29 - Tue, Oct 7
American Airlines Logo
7:59 pm - 5:30 pmSTL-BHD
15h 31m2 stops
American Airlines Logo
9:35 am - 9:29 pmBHD-STL
17h 54m2 stops
$706American Airlines
Find Deal
Mon, Sep 29 - Tue, Oct 7
Delta Logo
10:45 am - 9:00 pmSTL-BHD
28h 15m2 stops
Delta Logo
6:30 am - 4:50 pmBHD-STL
16h 20m2 stops
$801Delta
Find Deal
Sun, Mar 1 - Thu, Mar 5
Delta Logo
10:45 am - 9:00 pmSTL-BHD
28h 15m2 stops
Delta Logo
6:30 am - 4:55 pmBHD-STL
16h 25m2 stops
$802Delta
Find Deal
Sun, Mar 1 - Thu, Mar 5
British Airways Logo
10:36 am - 11:10 amSTL-BHD
18h 34m2 stops
British Airways Logo
7:00 pm - 11:49 pmBHD-STL
34h 49m2 stops
$916British Airways
Find Deal
Thu, Oct 16 - Sat, Oct 25
American Airlines Logo
4:25 pm - 4:45 pmSTL-BHD
19h 20m2 stops
American Airlines Logo
11:35 am - 10:29 pmBHD-STL
16h 54m2 stops
$1,347American Airlines
Find Deal
Sat, Nov 1 - Sat, Nov 8
Multiple Airlines Logo
1:30 pm - 4:25 pmSTL-BHD
20h 55m3 stops
Multiple Airlines Logo
5:55 pm - 7:38 pmBHD-STL
31h 43m3 stops
$2,032Multiple Airlines
Find Deal
Mon, Sep 29 - Tue, Oct 7
Multiple Airlines Logo
4:05 pm - 10:40 pmSTL-BFS
25h 35m3 stops
Multiple Airlines Logo
8:40 am - 1:55 pmBFS-STL
35h 15m3 stops
$2,789Multiple Airlines
Find Deal
Sat, Nov 1 - Sat, Nov 8
Multiple Airlines Logo
4:05 pm - 10:40 pmSTL-BFS
25h 35m3 stops
Multiple Airlines Logo
8:40 am - 1:55 pmBFS-STL
35h 15m2 stops
$2,804Multiple Airlines
Find Deal
Sat, Nov 1 - Sat, Nov 8
Multiple Airlines Logo
4:05 pm - 6:30 pmSTL-BFS
21h 25m2 stops
Multiple Airlines Logo
8:40 am - 1:55 pmBFS-STL
35h 15m2 stops
$2,903Multiple Airlines
Find Deal
Sat, Nov 1 - Sat, Nov 8

American Airlines flights from St. Louis to Belfast

Our best American Airlines deals on St. Louis to Belfast flight tickets
American Airlines
Sep 29
STL7:59 pmLambert-St Louis
15h 31m
2 stops
BHD5:30 pmBelfast City
Oct 7
BHD9:35 amBelfast City
17h 54m
2 stops
STL9:29 pmLambert-St Louis
American Airlines
Nov 1
STL4:25 pmLambert-St Louis
19h 20m
2 stops
BHD4:45 pmBelfast City
Nov 8
BHD11:35 amBelfast City
16h 54m
2 stops
STL10:29 pmLambert-St Louis

Delta flights from St. Louis to Belfast

Our best Delta deals on St. Louis to Belfast flight tickets
Delta
Mar 1
STL10:45 amLambert-St Louis
28h 15m
2 stops
BHD9:00 pmBelfast City
Mar 5
BHD6:30 amBelfast City
16h 20m
2 stops
STL4:50 pmLambert-St Louis
Delta
Mar 1
STL10:45 amLambert-St Louis
28h 15m
2 stops
BHD9:00 pmBelfast City
Mar 5
BHD6:30 amBelfast City
16h 25m
2 stops
STL4:55 pmLambert-St Louis

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 September 17, 2025.
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 - BFS

STLBFS

Lambert-St Louis

Mon 9/29

1:26 pm-11:10 pm

2 stops27h 44m

Belfast Intl

Tue 10/7

6:45 am-10:04 pm

2 stops21h 19m

$583

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Mon 9/29

7:59 pm-5:30 pm

2 stops15h 31m

Belfast City

Tue 10/7

9:35 am-9:29 pm

2 stops17h 54m

$706

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Sun 3/1

10:45 am-9:00 pm

2 stops28h 15m

Belfast City

Thu 3/5

6:30 am-4:50 pm

2 stops16h 20m

$801

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Sun 3/1

10:45 am-9:00 pm

2 stops28h 15m

Belfast City

Thu 3/5

6:30 am-4:55 pm

2 stops16h 25m

$802

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Thu 10/16

10:36 am-11:10 am

2 stops18h 34m

Belfast City

Sat 10/25

7:00 pm-11:49 pm

2 stops34h 49m

$916

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Sat 11/1

4:25 pm-4:45 pm

2 stops19h 20m

Belfast City

Sat 11/8

11:35 am-10:29 pm

2 stops16h 54m

$1,347

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Mon 9/29

1:30 pm-4:25 pm

3 stops20h 55m

Belfast City

Tue 10/7

5:55 pm-7:38 pm

3 stops31h 43m

$2,032

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Sat 11/1

4:05 pm-10:40 pm

3 stops25h 35m

Belfast Intl

Sat 11/8

8:40 am-1:55 pm

3 stops35h 15m

$2,789

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Sat 11/1

4:05 pm-10:40 pm

3 stops25h 35m

Belfast Intl

Sat 11/8

8:40 am-1:55 pm

2 stops35h 15m

$2,804

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Sat 11/1

4:05 pm-6:30 pm

2 stops21h 25m

Belfast Intl

Sat 11/8

8:40 am-1:55 pm

2 stops35h 15m

$2,903

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to Belfast from

How to get the cheapest flight ticket from St. Louis to Belfast

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to Belfast?

The cheapest day to depart from St. Louis to Belfast is on a Tuesday when prices can be found for as low as $674. When flying out on a Wednesday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Belfast for around $870.

What is the cheapest time of day to depart on your flight to Belfast?

Our data shows that the cheapest St. Louis to Belfast flights are usually those with departure times in the afternoon. Our users have found flights to Belfast in the afternoon for as low as $785. Try not to purchase tickets at noon because they tend to be around $1,429. Of course, these prices can vary depending on the time of year and what airport you fly to.

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

Direct flights

None
There are no direct flights from St. Louis to Belfast. There are no popular flight routes 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 15h 31m, 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 many operators does momondo search for flights from Lambert-St Louis Airport to Belfast?

  • 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.

Best airlines flying from St. Louis to Belfast

Compare and see reviews for airlines that fly from St. Louis to Belfast with momondo
Airline
Rating
Free Cancellation
Price
American AirlinesPriceFrom $674Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights

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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1 adult
Fri 10/17
Fri 10/24

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