$514 Cheap Flights from St. Louis (STL) to Castries (SLU)

View $514 flight on Wed, May 27, 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 $514 for one-way flights and $1,301 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Thu, Jan 28 - Mon, Feb 8
STL
St. Louis
SLU
Castries
$1,301 Roundtrip, found 3 days ago
$1,301
Roundtrip
found 3 days ago
Select United flight, departing Thu, Jan 28 from St. Louis to Castries, returning Mon, Feb 8, priced at $1,301 found 3 days ago

Alternative airports near Castries

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Hewanorra Intl. UVF. Cheapest option available. Average driving time to city center is 53 minutes. Flights from $980
UVF
Hewanorra Intl.
Cheapest
Average driving time to city center53 min
Flights from $980

Frequently asked questions

How much does a flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) cost?
You can find cheap one-way flights from $514 and cheap return flights from $1,301 St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) with Expedia. Return flights often range between $630 and $2002. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
The cheapest month to fly from STL to SLU is January when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you're able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
Enter STL to SLU and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
American Airlines is one of the cheapest airlines offering connecting flights from Lambert-St. Louis Intl. (STL) to George F. L. Charles (SLU) with a layover in Ronald Reagan Washington National (DCA), with round-trip tickets starting from around $575. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
To find a cheap flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
What is the earliest flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
The earliest flight from Lambert-St. Louis International Airport (STL) to George F. L. Charles Airport (SLU) usually departs at 5:00 AM. This seasonal service is operated by American Airlines, making it a great option for early risers heading to Castries. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
The most popular departure times for flights from St. Louis (STL) to Castries (SLU) are in the late morning, from 9am to 12pm. This accounts for around 23% of total traffic. Many major carriers, including American Airlines and Delta, offer flights during this window. Many travelers prefer this time because it allows for a relaxed start to their travel day.
How long does it take to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
Flying from STL to SLU with a connection usually takes about 21 hours 30 minutes, traveling roughly 2,474 miles. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
Business class seats are offered on the STL to SLU route with Air Canada.
How do I earn miles on a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) flight with Expedia?
It's easy to earn miles on a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Castries from Lambert-St. Louis Intl. (STL)?
If you're planning to travel to Castries from Lambert-St. Louis Intl. (STL), you can fly into George F. L. Charles (SLU) Some flights may connect through major hubs like Ronald Reagan Washington National (DCA), Pierre Elliott Trudeau Intl. (YUL), O'Hare Intl. (ORD) before reaching Castries. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) at the last minute?
Typically, booking a last minute flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) flight and hotel package?
Securing a St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles)?
If you booked your St. Louis, MO (STL-Lambert-St. Louis Intl.) to Castries (SLU-George F. L. Charles) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
George F. L. Charles
Roundtrip price
$1,301
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 January. 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 2026. You can also book with separate airlines for your outbound and return journeys, from $514 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

*Flight schedules are subject to change.

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*Available to One Key members.