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Cheap flights from St. Louis to Belfast from $419

This is the cheapest one-way 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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Find the cheapest flights from St. Louis to Belfast

Cheap round-trip flights

Logo
7:59 pm - 7:35 pmSTL-BHD
17h 36m2 stops
Logo
6:35 am - 7:10 pmBHD-STL
18h 35m2 stops
$730
Find Deal
Mon, Sep 29 - Thu, Oct 2
KLM Logo
5:50 pm - 4:55 pmSTL-BHD
17h 05m2 stops
KLM Logo
6:30 am - 4:48 pmBHD-STL
16h 18m2 stops
$744KLM
Find Deal
Sun, Sep 21 - Tue, Sep 30
Delta Logo
10:45 am - 9:00 pmSTL-BHD
28h 15m2 stops
Delta Logo
6:30 am - 4:50 pmBHD-STL
16h 20m2 stops
$799Delta
Find Deal
Sun, Mar 1 - Thu, Mar 5
Virgin Atlantic Logo
7:05 pm - 9:00 pmSTL-BHD
19h 55m2 stops
Virgin Atlantic Logo
6:30 am - 11:40 pmBHD-STL
23h 10m2 stops
$801Virgin Atlantic
Find Deal
Sun, Mar 1 - Thu, Mar 5
American Airlines Logo
2:11 pm - 3:30 pmSTL-BHD
19h 19m2 stops
American Airlines Logo
7:05 am - 6:20 pmBHD-STL
17h 15m2 stops
$809American Airlines
Find Deal
Fri, Sep 26 - Sat, Oct 4
British Airways Logo
7:59 pm - 3:40 pmSTL-BHD
13h 41m2 stops
British Airways Logo
4:20 pm - 9:26 amBHD-STL
23h 06m3 stops
$918British Airways
Find Deal
Mon, Sep 29 - Thu, Oct 2
British Airways Logo
6:00 am - 8:50 amSTL-BHD
20h 50m2 stops
British Airways Logo
4:15 pm - 9:26 amBHD-STL
23h 11m3 stops
$1,019British Airways
Find Deal
Fri, Sep 26 - Sat, Oct 4
Logo
4:50 pm - 9:55 pmSTL-BFS
24h 05m3 stops
Logo
5:45 am - 12:56 amBFS-STL
24h 11m3 stops
$1,117
Find Deal
Sun, Oct 26 - Sun, Nov 2
Logo
1:30 pm - 11:55 amSTL-BFS
16h 25m2 stops
Logo
12:35 pm - 1:30 pmBFS-STL
30h 55m2 stops
$1,156
Find Deal
Fri, Sep 26 - Sat, Oct 4
Logo
1:30 pm - 4:55 pmSTL-BHD
21h 25m3 stops
Logo
5:25 pm - 7:38 pmBHD-STL
32h 13m3 stops
$1,274
Find Deal
Sun, Sep 21 - Tue, Sep 30

British Airways flights from St. Louis to Belfast

Our best British Airways deals on St. Louis to Belfast flight tickets
British Airways
Sep 29
STL7:59 pmLambert-St Louis
13h 41m
2 stops
BHD3:40 pmBelfast City
Oct 2
BHD4:20 pmBelfast City
23h 06m
3 stops
STL9:26 amLambert-St Louis
$918
Find similar
British Airways
Sep 26
STL6:00 amLambert-St Louis
20h 50m
2 stops
BHD8:50 amBelfast City
Oct 4
BHD4:15 pmBelfast City
23h 11m
3 stops
STL9:26 amLambert-St Louis
$1,019
Find similar

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 11, 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 - BHD

STLBHD

Lambert-St Louis

Mon 9/29

7:59 pm-7:35 pm

2 stops17h 36m

Belfast City

Thu 10/2

6:35 am-7:10 pm

2 stops18h 35m

$730

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Sun 9/21

5:50 pm-4:55 pm

2 stops17h 05m

Belfast City

Tue 9/30

6:30 am-4:48 pm

2 stops16h 18m

$744

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

$799

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Sun 3/1

7:05 pm-9:00 pm

2 stops19h 55m

Belfast City

Thu 3/5

6:30 am-11:40 pm

2 stops23h 10m

$801

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Fri 9/26

2:11 pm-3:30 pm

2 stops19h 19m

Belfast City

Sat 10/4

7:05 am-6:20 pm

2 stops17h 15m

$809

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Mon 9/29

7:59 pm-3:40 pm

2 stops13h 41m

Belfast City

Thu 10/2

4:20 pm-9:26 am

3 stops23h 06m

$918

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Fri 9/26

6:00 am-8:50 am

2 stops20h 50m

Belfast City

Sat 10/4

4:15 pm-9:26 am

3 stops23h 11m

$1,019

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Sun 10/26

4:50 pm-9:55 pm

3 stops24h 05m

Belfast Intl

Sun 11/2

5:45 am-12:56 am

3 stops24h 11m

$1,117

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Fri 9/26

1:30 pm-11:55 am

2 stops16h 25m

Belfast Intl

Sat 10/4

12:35 pm-1:30 pm

2 stops30h 55m

$1,156

St. LouisBelfast

STL - BHD

STLBHD

Lambert-St Louis

Sun 9/21

1:30 pm-4:55 pm

3 stops21h 25m

Belfast City

Tue 9/30

5:25 pm-7:38 pm

3 stops32h 13m

$1,274

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 12 resultsSorted by cheapest first
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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.
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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 13h 41m, 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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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