$592 Cheap Flights from St. Louis (STL) to Castries (SLU)

View $592 flight on Sun, Jan 18, 2026Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to George F. L. Charles Airport (SLU)

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Cheap Flights from St. Louis to Castries (STL-SLU)

Prices were available within the past 7 days and start at $592 for one-way flights and $1,438 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Tue, Apr 7 - Mon, Apr 13
STL
St. Louis
SLU
Castries
$1,438 Roundtrip, found 3 hours ago
$1,438
Roundtrip
found 3 hours ago
Select United flight, departing Tue, Apr 7 from St. Louis to Castries, returning Mon, Apr 13, priced at $1,438 found 3 hours ago

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU) cost?
Secure a cheap one-way flight from $592 or cheap return flight from $1,438 from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU)?
April is the least expensive month to fly from STL to SLU. Traveling during quieter months is often the key to landing a great deal.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU)?
Expedia's filter tool lets you easily compare airlines, flight times and fares all in one place. Customize the search to your preferences, then sort by "Price (lowest to highest)" to find out which carrier offers the cheapest STL to SLU flight.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU)?
You'll have to catch a flight with a layover if you're traveling from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU). There are no daily direct flights on this route. However, just filter your search to include one or two stops to find the best option for your trip.
What day of the week has the most flights from STL to SLU?
Generally you'll find the greatest selection of flight options on a Friday. Tuesdays are often the quietest.* But this can vary depending on the airline, season 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 George F. L. Charles Airport (SLU)?
To avoid potential delays on the Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU) route, aim to travel before 3 PM. Later departures have a 22% higher chance of being canceled.**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 George F. L. Charles Airport (SLU) last-minute?
Waiting until just before your departure to book your flight from STL to SLU often results in higher prices. While it's possible to find some last-minute offers, they're not always guaranteed. Allow some flexibility in your schedule to maximize your chances of landing a bargain.
Is it cheaper to book a STL to SLU flight and hotel package?
You'll typically save money by securing a STL to SLU flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's simple to manage everything in one convenient place. Once you've selected your ideal accommodations and flights, consider other add-ons like activities, car rentals and tours.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to George F. L. Charles Airport (SLU)?
In most instances, you can reschedule or cancel your STL to SLU flight. However, there may be additional fees, especially if your booking was made more than 24 hours ago. Check your itinerary for the airline's policies and fees on flight changes, or if you want more information, head to our Customer Service portal.

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
George F. L. Charles
Roundtrip price
$1,438
Distance
2473 mi

Book with confidence

St. Louis to Castries Flights

The cheapest times to fly from St. Louis to Castries

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 Castries are during the month of April. You can find some of the cheapest flights from St. Louis to Castries with Expedia's search tool and vast selection of airlines.

 

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

Sunday is one of the best days to book for cheap flights from St. Louis to Castries: 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 Castries

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 Castries in 2025. You can also book with separate airlines for your outbound and return journeys, from $592 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 Castries 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 Castries 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.

 

St. Louis to Castries Flights

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*Available to One Key members.