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Cheap flights from St. Louis to Belfast from $1,117

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 10/26. 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
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
4:50 pm - 9:30 pmSTL-BFS
23h 40m2 stops
Logo
5:45 am - 12:56 amBFS-STL
24h 11m3 stops
$1,327
Find Deal
Sun, Oct 26 - Sun, Nov 2
Logo
4:05 pm - 9:00 pmSTL-BFS
22h 55m2 stops
Logo
9:40 am - 9:37 pmBFS-STL
17h 57m3 stops
$1,610
Find Deal
Fri, Sep 26 - Sat, Oct 4
Logo
4:05 pm - 4:10 pmSTL-BFS
18h 05m2 stops
Logo
9:55 pm - 7:38 pmBFS-STL
27h 43m3 stops
$1,826
Find Deal
Mon, Sep 29 - Thu, Oct 2
Logo
9:15 am - 11:20 amSTL-BFS
20h 05m3 stops
Logo
9:55 pm - 7:38 pmBFS-STL
27h 43m3 stops
$1,864
Find Deal
Mon, Sep 29 - Thu, Oct 2
Logo
9:15 am - 11:55 amSTL-BFS
20h 40m3 stops
Logo
9:40 am - 9:37 pmBFS-STL
17h 57m3 stops
$1,918
Find Deal
Fri, Sep 26 - Sat, Oct 4

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Belfast Intl Airport 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 Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

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 - BFS

STLBFS

Lambert-St Louis

Sun 10/26

4:50 pm-9:30 pm

2 stops23h 40m

Belfast Intl

Sun 11/2

5:45 am-12:56 am

3 stops24h 11m

$1,327

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Fri 9/26

4:05 pm-9:00 pm

2 stops22h 55m

Belfast Intl

Sat 10/4

9:40 am-9:37 pm

3 stops17h 57m

$1,610

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Mon 9/29

4:05 pm-4:10 pm

2 stops18h 05m

Belfast Intl

Thu 10/2

9:55 pm-7:38 pm

3 stops27h 43m

$1,826

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Mon 9/29

9:15 am-11:20 am

3 stops20h 05m

Belfast Intl

Thu 10/2

9:55 pm-7:38 pm

3 stops27h 43m

$1,864

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Fri 9/26

9:15 am-11:55 am

3 stops20h 40m

Belfast Intl

Sat 10/4

9:40 am-9:37 pm

3 stops17h 57m

$1,918

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 Intl Airport

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 Intl Airport?

The cheapest day to depart on your flight to Belfast Intl Airport is on a Tuesday when prices can be found for as low as $674. This is often the case because there is less demand to fly during this day of the week. 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 Intl Airport for around $870.

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

In the afternoon is the cheapest time of day to fly from St. Louis to Belfast Intl Airport when you can find flight prices for as low as $785. Flying to Belfast Intl Airport in the afternoon is an ideal time because this is during off-peak travel hours. In contrast, the most expensive time of day to depart to Belfast Intl Airport is at noon when prices are around $1,429.

When to book flights from St. Louis to Belfast Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Belfast Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Belfast Intl Airport (STL to BFS) flight deals and tips

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

Direct flights

None
There are no direct flights from St. Louis to Belfast Intl Airport. There are no popular flight routes from St. Louis to Belfast Intl Airport.
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  • How far is Lambert-St Louis to Belfast Intl by plane?

    Belfast Intl is 3879.0 mi away from Lambert-St Louis. A reasonable flight in good conditions will take 16h 25m.

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

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

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Belfast Intl Airport?

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

    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 Intl Airport.

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

    The travel and health documents required for your trip to Belfast Intl Airport 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 Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular airline from St. Louis to Belfast Intl Airport?

Best airlines flying from St. Louis to Belfast Intl Airport

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

Traveling to a place near Belfast?

Book flights to Belfast if you plan to visit one of these locations
Newry
Armagh
Cookstown
Dungannon

Why use momondo?

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

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from St. Louis to Belfast. momondo saves you time and could save you money on your trip.

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

All flight searches from St. Louis to Belfast on momondo can be filtered to show those which offer 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?

If you are not ready to book a flight from St. Louis to Belfast now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Belfast and let you know when they change.

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