$518 Cheap Flights from San Antonio (SAT) to Castries (SLU)

View $518 flight on Tue, Mar 10, 2026Opens in a new window

Popular airlines from San Antonio International Airport (SAT) to George F. L. Charles Airport (SLU)

Cheap Flights from San Antonio to Castries (SAT-SLU)

Prices were available within the past 7 days and start at $518 for one-way flights and $1,595 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Wed, Dec 17 - Fri, Dec 19
SAT
San Antonio
SLU
Castries
$1,595 Roundtrip, found 4 days ago
$1,595
Roundtrip
found 4 days ago
Select United flight, departing Wed, Dec 17 from San Antonio to Castries, returning Fri, Dec 19, priced at $1,595 found 4 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 $1,347
UVF
Hewanorra Intl.
Cheapest
Average driving time to city center53 min
Flights from $1,347
Flights from San Antonio (SAT) to Castries (SLU)
Origin airport
San Antonio Intl.
Destination airport
George F. L. Charles
Roundtrip price
$1,595
Distance
2616 mi

San Antonio to Castries Flights

The cheapest times to fly from San Antonio 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 San Antonio to Castries are during the month of December. You can find some of the cheapest flights from San Antonio to Castries with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from San Antonio to Castries

Sunday is one of the best days to book for cheap flights from San Antonio 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 San Antonio 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 San Antonio to Castries in 2026. You can also book with separate airlines for your outbound and return journeys, from $518 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 San Antonio 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 San Antonio 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.

 

Frequently asked questions

How much does a flight from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU) cost?
Lock in a cheap one-way flight from $518 or cheap return flight from $1,595 from San Antonio Intl. Airport (SAT) 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 deals on this route.
What is the cheapest month to fly from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU)?
Planning your getaway for December may help you find better deals, as it's the cheapest month for flights between SAT and SLU. You'll typically find the lowest prices during the off-season.
What is the cheapest airline that flies from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU)?
Expedia's filter tool lets you easily compare travel time, airlines and fares all in one place. Customize the search to your preferences, then sort by "Price (lowest to highest)" to see which carrier offers the cheapest SAT to SLU flight.
How many flights per day from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU)?
You'll need to catch a flight with a layover if you're traveling from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU). Direct flights don't operate daily 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 SAT to SLU?
Typically you'll find the widest variety of flight choices on a Friday. Tuesdays tend to be the quietest.* But this can vary based on the airline, time of year 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 San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU)?
Book a flight from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU) that leaves before 3 PM to reduce the risk of delays and cancellations. Departures later than this are on average 22% more likely to be 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 San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU) last-minute?
Holding off until just before your departure to book a flight from SAT to SLU often results in higher prices. While you might find some last-minute deals, there's no guarantee. Be flexible with your itinerary to maximize your chances of getting a bargain.
Is it cheaper to book a SAT to SLU flight and hotel package?
You'll generally save money by booking a SAT 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 easy to manage it all in one convenient place. After choosing your preferred flights and accommodations, you can add extras such as tours, car rentals and activities.
Can I cancel or change the date of my flight from San Antonio Intl. Airport (SAT) to George F. L. Charles Airport (SLU)?
If you booked your SAT to SLU flight within the last 24 hours, you may be able to cancel or modify it without any 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, go to our Customer Service portal if you want more information.

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*Available to One Key members.