Latest deals
When to book
FAQs
Price Alerts

Cheap flights from St. Louis to Belfast from $1,358

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 6/5. 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

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
2:15 pm - 9:50 pm
STL
-
BFS
25h 35m
2 stops
Multiple Airlines Logo
6:35 am - 8:25 pm
BFS
-
STL
19h 50m
2 stops
$1,358Multiple Airlines
Fri, Jun 5 - Thu, Jun 11
Multiple Airlines Logo
1:05 pm - 9:50 pm
STL
-
BFS
26h 45m
3 stops
Multiple Airlines Logo
6:35 am - 8:25 pm
BFS
-
STL
19h 50m
2 stops
$1,449Multiple Airlines
Fri, Jun 5 - Thu, Jun 11
Multiple Airlines Logo
2:15 pm - 6:55 pm
STL
-
BFS
22h 40m
2 stops
Multiple Airlines Logo
9:05 pm - 8:25 pm
BFS
-
STL
29h 20m
2 stops
$1,450Multiple Airlines
Thu, Jun 11 - Thu, Jun 18
Multiple Airlines Logo
2:15 pm - 6:55 pm
STL
-
BFS
22h 40m
2 stops
Multiple Airlines Logo
9:05 pm - 5:23 pm
BFS
-
STL
26h 18m
3 stops
$1,468Multiple Airlines
Thu, Jun 11 - Thu, Jun 18
Multiple Airlines Logo
1:05 pm - 6:55 pm
STL
-
BFS
23h 50m
3 stops
Multiple Airlines Logo
6:10 am - 8:07 pm
BFS
-
STL
19h 57m
3 stops
$1,721Multiple Airlines
Thu, Jun 11 - Thu, Jun 18

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

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 April 29, 2026.
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

Cheapest round-trip

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Fri 6/5

2:15 pm-9:50 pm

2 stops25h 35m

Belfast Intl

Thu 6/11

6:35 am-8:25 pm

2 stops19h 50m

$1,358

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Fri 6/5

1:05 pm-9:50 pm

3 stops26h 45m

Belfast Intl

Thu 6/11

6:35 am-8:25 pm

2 stops19h 50m

$1,449

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Thu 6/11

2:15 pm-6:55 pm

2 stops22h 40m

Belfast Intl

Thu 6/18

9:05 pm-8:25 pm

2 stops29h 20m

$1,450

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Thu 6/11

2:15 pm-6:55 pm

2 stops22h 40m

Belfast Intl

Thu 6/18

9:05 pm-5:23 pm

3 stops26h 18m

$1,468
Quickest round-trip

St. LouisBelfast

STL - BFS

STLBFS

Lambert-St Louis

Thu 6/11

1:05 pm-6:55 pm

3 stops23h 50m

Belfast Intl

Thu 6/18

6:10 am-8:07 pm

3 stops19h 57m

$1,721

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

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

Fastest flight time

12h 05m

Direct flights

None
The fastest flight from St. Louis to Belfast Intl Airport takes 12h 05m
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.
Search flight deals

Frequently asked questions about flying from St. Louis to Belfast Intl Airport

  • 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 12h 05m.

  • 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 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.

Frequently asked questions about flying from St. Louis to Belfast Intl Airport

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

    Price Alerts will notify you by email when the price for flights to Belfast Intl Airport 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 Intl Airport 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.

Traveling to a place near Belfast?

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

An easier way to manage your Belfast Intl Airport trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Fri 5/29
Fri 6/5
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Belfast

Popular cities in the United Kingdom

Popular flights according to clicks in the last 7 days on momondo
Flights to London Heathrow Airportfrom $495
Flights to London Gatwick Airportfrom $478
Flights to London Stansted Airportfrom $535
Flights to London City Airportfrom $697
Flights to London Luton Airportfrom $532
Flights to Glasgow Intl Airportfrom $595
Flights to London Southend Airportfrom $723
Flights to Belfast City Airportfrom $711