$423 Cheap United flights St. Louis (STL) to Shannon (SNN)

View $423 flight on Tue, Oct 7, 2025Opens in a new window

$423 Cheap United flights St. Louis (STL) to Shannon (SNN)

Prices were available within the past 7 days and start at $423 for one-way flights and $586 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Mon, Apr 27 - Mon, May 4
STL
St. Louis
SNN
Shannon
$586 Roundtrip, found 17 hours ago
$586
Roundtrip
found 17 hours ago
Select United flight, departing Mon, Apr 27 from St. Louis to Shannon, returning Mon, May 4, priced at $586 found 17 hours ago
United
Mon, Apr 27 - Mon, May 4
STL
St. Louis
SNN
Shannon
$590 Roundtrip, found 17 hours ago
$590
Roundtrip
found 17 hours ago
Select United flight, departing Mon, Apr 27 from St. Louis to Shannon, returning Mon, May 4, priced at $590 found 17 hours ago
United
Mon, Apr 27 - Mon, May 4
STL
St. Louis
SNN
Shannon
$591 Roundtrip, found 17 hours ago
$591
Roundtrip
found 17 hours ago
Select United flight, departing Mon, Apr 27 from St. Louis to Shannon, returning Mon, May 4, priced at $591 found 17 hours ago
United
Mon, Oct 13 - Tue, Oct 21
STL
St. Louis
SNN
Shannon
$641 Roundtrip, found 8 hours ago
$641
Roundtrip
found 8 hours ago
Select United flight, departing Mon, Oct 13 from St. Louis to Shannon, returning Tue, Oct 21, priced at $641 found 8 hours ago
United
Tue, Oct 7 - Tue, Oct 14
STL
St. Louis
SNN
Shannon
$645 Roundtrip, found 8 hours ago
$645
Roundtrip
found 8 hours ago
Select United flight, departing Tue, Oct 7 from St. Louis to Shannon, returning Tue, Oct 14, priced at $645 found 8 hours ago
United
Tue, Oct 7 - Tue, Oct 14
STL
St. Louis
SNN
Shannon
$646 Roundtrip, found 8 hours ago
$646
Roundtrip
found 8 hours ago
Select United flight, departing Tue, Oct 7 from St. Louis to Shannon, returning Tue, Oct 14, priced at $646 found 8 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
Popular airline
British Airways
Distance
3826 mi

Frequently asked questions

How much is a United Airlines flight from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN)?
Scoring cheap one-way United Airlines flights from STL to SNN from $423 on Expedia is easy — just filter by "Price (lowest to highest)." Or check out our budget-friendly round-trip fares from $586 for your next exciting vacation.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.
What is the cheapest month to fly from STL to SNN with United Airlines?
United Airlines flights to Shannon are typically more affordable in the low-season months of January and February. Whether you're searching for a one-way or a return ticket, you could find a better deal then.
What is the cheapest time to book flights from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN) with United Airlines?
Search for United Airlines flights from STL to SNN about one month before you want to leave. The cheapest time to reserve an international flight is generally 18 to 29 days ahead of your departure date when you can save 17% versus booking four to five months in advance. Regardless of ticket type or itinerary, the best day to book international airfare is usually Sunday. Friday is often the most expensive. Travelers who book on a Sunday can save an average of 17% compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.
Does United Airlines fly nonstop from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN)?
To figure out if there's a direct trip from STL to SNN with United Airlines or other airlines, use our "Nonstop" filter when browsing for tickets.
What is the earliest United Airlines flight from STL to SNN?
To find the earliest departure from STL to SNN with United Airlines, sort your results by "Morning" and "Early Morning." Choosing an early flight usually means you're less likely to experience cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports does United Airlines fly into in Shannon?
Hop on a United Airlines flight from Lambert-St. Louis Intl. Airport (STL) to Shannon, and you'll probably arrive at Shannon Airport (SNN). This is the airline's primary hub in this city.
Why fly with United Airlines from STL to SNN?
A rewarding loyalty program and the ability to collect points through United Mileage Plus are the start of the reasons to travel from STL to SNN with United Airlines. Plus, when you sign up to our One Key™ program, you can earn OneKeyCash™* in addition to any airline loyalty program earnings. It's yours to spend on future travel plans.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.
Can I change or cancel my United Airlines flight from Lambert-St. Louis Intl. Airport (STL) to Shannon Airport (SNN)?
Depending on the ticket type you purchased, a fee will generally apply if you cancel or reschedule your booking more than 24 hours after it has been confirmed. To find flexible fares, select our "No cancel fee" or "Changes included" filter when searching for flights. For more information on modifying or canceling your reservation, go to "Trips," select your flight and click on "Manage Booking."

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*Available to One Key members.