$445 Cheap Flights from St. Louis (STL) to Shannon (SNN)

View $445 flight on Sun, Aug 31, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Shannon Airport (SNN)

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Find available prices by choosing your travel dates.

Cheap Flights from St. Louis to Shannon (STL-SNN)

Prices were available within the past 7 days and start at $445 for one-way flights and $606 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, Aug 12 - Tue, Aug 26
STL
St. Louis
SNN
Shannon
$606 Roundtrip, found 4 days ago
$606
Roundtrip
found 4 days ago
Select Delta flight, departing Tue, Aug 12 from St. Louis to Shannon, returning Tue, Aug 26, priced at $606 found 4 days ago
Delta
Mon, Sep 8 - Tue, Sep 16
STL
St. Louis
SNN
Shannon
$615 Roundtrip, found 11 hours ago
$615
Roundtrip
found 11 hours ago
Select Delta flight, departing Mon, Sep 8 from St. Louis to Shannon, returning Tue, Sep 16, priced at $615 found 11 hours ago
United
Wed, May 7 - Thu, May 15
STL
St. Louis
SNN
Shannon
$615 Roundtrip, found 4 days ago
$615
Roundtrip
found 4 days ago
Select United flight, departing Wed, May 7 from St. Louis to Shannon, returning Thu, May 15, priced at $615 found 4 days ago
Delta
Fri, Aug 15 - Fri, Aug 22
STL
St. Louis
SNN
Shannon
$630 Roundtrip, found 4 days ago
$630
Roundtrip
found 4 days ago
Select Delta flight, departing Fri, Aug 15 from St. Louis to Shannon, returning Fri, Aug 22, priced at $630 found 4 days ago
KLM
Mon, Sep 8 - Tue, Sep 16
STL
St. Louis
SNN
Shannon
$641 Roundtrip, found 11 hours ago
$641
Roundtrip
found 11 hours ago
Select KLM flight, departing Mon, Sep 8 from St. Louis to Shannon, returning Tue, Sep 16, priced at $641 found 11 hours ago
KLM
Mon, Aug 18 - Tue, Aug 26
STL
St. Louis
SNN
Shannon
$643 Roundtrip, found 4 days ago
$643
Roundtrip
found 4 days ago
Select KLM flight, departing Mon, Aug 18 from St. Louis to Shannon, returning Tue, Aug 26, priced at $643 found 4 days ago
Delta
Sun, Aug 31 - Tue, Sep 9
STL
St. Louis
SNN
Shannon
$650 Roundtrip, found 11 hours ago
$650
Roundtrip
found 11 hours ago
Select Delta flight, departing Sun, Aug 31 from St. Louis to Shannon, returning Tue, Sep 9, priced at $650 found 11 hours ago
KLM
Sat, Sep 6 - Tue, Sep 16
STL
St. Louis
SNN
Shannon
$652 Roundtrip, found 11 hours ago
$652
Roundtrip
found 11 hours ago
Select KLM flight, departing Sat, Sep 6 from St. Louis to Shannon, returning Tue, Sep 16, priced at $652 found 11 hours ago
American Airlines
Wed, Nov 12 - Tue, Nov 18
STL
St. Louis
SNN
Shannon
$780 Roundtrip, found 4 hours ago
$780
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Wed, Nov 12 from St. Louis to Shannon, returning Tue, Nov 18, priced at $780 found 4 hours ago
Air Canada
Mon, May 12 - Tue, May 27
STL
St. Louis
SNN
Shannon
$882 Roundtrip, found 4 hours ago
$882
Roundtrip
found 4 hours ago
Select Air Canada flight, departing Mon, May 12 from St. Louis to Shannon, returning Tue, May 27, priced at $882 found 4 hours ago
Flights from St. Louis (STL) to Shannon (SNN)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Shannon
Airlines serving
Air Canada, Air France, American Airlines, British Airways, Delta, Lufthansa, United
Roundtrip price
$606
Distance
3826 mi

St. Louis to Shannon Flights

The cheapest times to fly from St. Louis to Shannon

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Shannon are during the month of August. You can find some of the cheapest flights from St. Louis to Shannon with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Shannon

Sunday is one of the best days to book for cheap flights from St. Louis to Shannon: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to Shannon

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Shannon in 2025. You can also book with separate airlines for your outbound and return journeys, from $445 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Shannon flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Shannon airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN) cost?
Discover the latest flight deals from STL to SNN by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from STL to SNN?
The cheapest flights from STL to SNN are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from STL to SNN?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from STL to SNN. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN)?
There are no daily direct flights available from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN). But you can book flights with layovers. Filter your search on Expedia to include one or more stops, and you’ll be soaring above the clouds before you know it.
What day of the week has the most flights from STL to SNN?
Typically you’ll find the widest variety of flight choices on a Friday. Tuesdays are often the quietest.* But this can change depending on the season, carrier and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN)?
Opt for a flight from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN) that takes off before 3 PM to reduce the likelihood of delays and cancellations. Departures after this time have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN) last-minute?
Booking your plane ticket from STL to SNN just before your getaway is usually more expensive. But if there’s some wiggle room with your departure dates and times, you could snag a cheap last-minute fare.
Is it cheaper to book a STL to SNN flight and hotel package?
You’ll generally save money by securing a STL to SNN flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it’s easy to manage it all in one place. Once you’ve selected your preferred flights and accommodations, consider adding extras such as car rentals, tours and activities.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN)?
If you booked your STL to SNN flight in the last 24 hours, you may be able to cancel or modify it without fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes beyond that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, visit our Customer Service portal for further details.

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*Available to One Key members.