$591 Cheap Aer Lingus flights St. Louis (STL) to Southampton (SOU)

View $591 flight on Mon, Sep 1, 2025Opens in a new window

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$591 Cheap Aer Lingus flights St. Louis (STL) to Southampton (SOU)

Prices were available within the past 7 days and start at $591 for one-way flights and $939 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Aer Lingus
Mon, Aug 4 - Thu, Aug 21
STL
St. Louis
SOU
Southampton
$939 Roundtrip, found 4 days ago
$939
Roundtrip
found 4 days ago
Select Aer Lingus flight, departing Mon, Aug 4 from St. Louis to Southampton, returning Thu, Aug 21, priced at $939 found 4 days ago
Aer Lingus
Wed, Aug 27 - Wed, Sep 17
STL
St. Louis
SOU
Southampton
$961 Roundtrip, found 4 days ago
$961
Roundtrip
found 4 days ago
Select Aer Lingus flight, departing Wed, Aug 27 from St. Louis to Southampton, returning Wed, Sep 17, priced at $961 found 4 days ago
Aer Lingus
Sun, Sep 14 - Wed, Sep 24
STL
St. Louis
SOU
Southampton
$966 Roundtrip, found 7 hours ago
$966
Roundtrip
found 7 hours ago
Select Aer Lingus flight, departing Sun, Sep 14 from St. Louis to Southampton, returning Wed, Sep 24, priced at $966 found 7 hours ago
Aer Lingus
Wed, Aug 27 - Tue, Sep 16
STL
St. Louis
SOU
Southampton
$969 Roundtrip, found 4 days ago
$969
Roundtrip
found 4 days ago
Select Aer Lingus flight, departing Wed, Aug 27 from St. Louis to Southampton, returning Tue, Sep 16, priced at $969 found 4 days ago
Aer Lingus
Wed, Aug 27 - Thu, Sep 18
STL
St. Louis
SOU
Southampton
$976 Roundtrip, found 4 days ago
$976
Roundtrip
found 4 days ago
Select Aer Lingus flight, departing Wed, Aug 27 from St. Louis to Southampton, returning Thu, Sep 18, priced at $976 found 4 days ago
Aer Lingus
Sat, Aug 23 - Wed, Sep 10
STL
St. Louis
SOU
Southampton
$995 Roundtrip, found 4 days ago
$995
Roundtrip
found 4 days ago
Select Aer Lingus flight, departing Sat, Aug 23 from St. Louis to Southampton, returning Wed, Sep 10, priced at $995 found 4 days ago
Flights from St. Louis (STL) to Southampton (SOU)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Southampton
Airlines serving
Aer Lingus, Delta, KLM, Virgin Atlantic
Popular airline
Aer Lingus
Distance
4170 mi

Frequently asked questions

How much is an Aer Lingus flight from Lambert-St. Louis Intl. Airport (STL) to Southampton Airport (SOU)?
Scoring cheap one-way Aer Lingus flights from STL to SOU from $591 on Expedia couldn't be easier --- just filter by "Price (lowest to highest)." Alternatively, check out our budget-friendly return fares from $939 for your next adventure.**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 SOU with Aer Lingus?
Aer Lingus flights to Southampton are usually more affordable in the low-season months of January and February. Whether you're after a one-way or round-trip ticket, you could score a better deal then.
What is the cheapest time to book flights from Lambert-St. Louis Intl. Airport (STL) to Southampton Airport (SOU) with Aer Lingus?
Getting the best Aer Lingus deals from STL to SOU often comes down to booking at the right moment. You can save 17% on international flights when you book 18 to 29 days before takeoff instead of four to five months ahead. As an added bonus, you can pocket 17% on average by buying your fare on a Sunday rather than a Friday, which is often the most expensive day to book.* It's a good idea to start checking out flights about one month before your departure date.*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 Aer Lingus fly nonstop from Lambert-St. Louis Intl. Airport (STL) to Southampton Airport (SOU)?
To see if there's a direct route from STL to SOU with Aer Lingus or another airline, check the "Nonstop" filter when browsing for flights.
What is the earliest Aer Lingus flight from STL to SOU?
Find Aer Lingus's earliest flights from STL to SOU by using the "Early Morning" and "Morning" filters. Not only will you get to where you're going sooner, early departures also have a 20% less chance of being canceled.**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 Aer Lingus fly into in Southampton?
Aer Lingus flights from Lambert-St. Louis Intl. Airport (STL) to Southampton come in to land at Southampton Airport (SOU). This is the main entry point here.
What kind of luggage can I take on an Aer Lingus flight from Lambert-St. Louis Intl. Airport (STL) to Southampton Airport (SOU)?
Aer Lingus lets passengers bring 1 checked-in bag weighing up to 50 lb with maximum dimensions of 62 inches on standard economy flights from STL to SOU. Additionally, you can bring 1 cabin bag with you in the cabin. This carry-on luggage must not exceed 21 inches x 15 inches x 9 inches and weigh less than 22 lb. Baggage rules can vary depending on your cabin class and fare type, so check your booking or Aer Lingus's website to avoid any unexpected fees at the airport.
Why fly with Aer Lingus from STL to SOU?
Jetting off from STL to SOU with Aer Lingus means enjoying a host of benefits, including a rewarding loyalty program and a 4-star airline rating. Plus, when booking through Expedia, One Key™ members can earn OneKeyCash™* to use on select future travel purchases. That's in addition to the Aer Lingus AerClub points you can earn with Aer Lingus.*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 Aer Lingus flight from Lambert-St. Louis Intl. Airport (STL) to Southampton Airport (SOU)?
Depending on the ticket type you purchased, a fee will generally apply if you cancel or reschedule your flight more than 24 hours after confirmation. To find tickets with more flexibility, select our "No cancel fee" or "Changes included" filter when you look for flights. To learn more about changing or canceling your reservation, visit "Trips," select your flight and click on "Manage Booking."

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*Available to One Key members.