$153 Cheap Flights from St. Louis (STL) to Ponce (PSE)

View $153 flight on Sun, Oct 5, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Ponce (PSE-Mercedita)

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Cheap Flights from St. Louis to Ponce (STL-PSE)

Prices were available within the past 7 days and start at $153 for one-way flights and $536 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Fri, Dec 12 - Fri, Dec 26
STL
St. Louis
PSE
Ponce
$536 Roundtrip, found 4 days ago
$536
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Fri, Dec 12 from St. Louis to Ponce, returning Fri, Dec 26, priced at $536 found 4 days ago
Frontier Airlines
Mon, Dec 22 - Sat, Jan 10
STL
St. Louis
PSE
Ponce
$544 Roundtrip, found 11 hours ago
$544
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Mon, Dec 22 from St. Louis to Ponce, returning Sat, Jan 10, priced at $544 found 11 hours ago
Frontier Airlines
Wed, Dec 17 - Fri, Dec 26
STL
St. Louis
PSE
Ponce
$554 Roundtrip, found 4 days ago
$554
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Wed, Dec 17 from St. Louis to Ponce, returning Fri, Dec 26, priced at $554 found 4 days ago
Frontier Airlines
Tue, Dec 23 - Sat, Jan 10
STL
St. Louis
PSE
Ponce
$561 Roundtrip, found 11 hours ago
$561
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Tue, Dec 23 from St. Louis to Ponce, returning Sat, Jan 10, priced at $561 found 11 hours ago
Frontier Airlines
Sun, Dec 14 - Fri, Dec 26
STL
St. Louis
PSE
Ponce
$604 Roundtrip, found 4 days ago
$604
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Sun, Dec 14 from St. Louis to Ponce, returning Fri, Dec 26, priced at $604 found 4 days ago
Frontier Airlines
Mon, Dec 22 - Thu, Jan 8
STL
St. Louis
PSE
Ponce
$609 Roundtrip, found 11 hours ago
$609
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Mon, Dec 22 from St. Louis to Ponce, returning Thu, Jan 8, priced at $609 found 11 hours ago
Frontier Airlines
Tue, Dec 23 - Thu, Jan 8
STL
St. Louis
PSE
Ponce
$626 Roundtrip, found 11 hours ago
$626
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Tue, Dec 23 from St. Louis to Ponce, returning Thu, Jan 8, priced at $626 found 11 hours ago
Frontier Airlines
Mon, Dec 22 - Mon, Jan 5
STL
St. Louis
PSE
Ponce
$794 Roundtrip, found 11 hours ago
$794
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Mon, Dec 22 from St. Louis to Ponce, returning Mon, Jan 5, priced at $794 found 11 hours ago
Frontier Airlines
Tue, Dec 23 - Mon, Jan 5
STL
St. Louis
PSE
Ponce
$811 Roundtrip, found 11 hours ago
$811
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Tue, Dec 23 from St. Louis to Ponce, returning Mon, Jan 5, priced at $811 found 11 hours ago

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE) cost?
Lock in a cheap one-way flight from $153 or cheap return flight from $536 from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE) 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 Mercedita Airport (PSE)?
The cheapest month to fly from STL to PSE is December, when there's less demand. Off-peak months are usually when airlines offer lower prices between these airports.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE)?
To find the cheapest airline flying from STL to PSE, use Expedia's filter tool. Customize your search based on your travel needs, such as preferred carriers and flight duration. You can then sort your results by "Price (lowest to highest)" to see the cheapest flights first.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE)?
Nonstop flights from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE) aren't available daily, so you'll have to take a flight with a layover. Explore your options with Expedia's filter tool. Enter your dates and click on either "1 Stop" or "2+ Stops."
What day of the week has the most flights from STL to PSE?
You'll usually find Tuesday the quietest day for flights, while Fridays tend to be the busiest.* However this can vary from season to season and during peak travel times or public holidays.*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 Mercedita Airport (PSE)?
To land at Mercedita Airport (PSE) on time, book a flight that leaves Lambert-St. Louis Intl. Airport (STL) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**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.
What airports do you fly into for Ponce from Lambert-St. Louis Intl. Airport (STL)?
If you're boarding a direct flight from Lambert-St. Louis Intl. Airport (STL) to Ponce, Luis Munoz Marin Intl. Airport (SJU) is the only airport you can land at.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE) last-minute?
Waiting until right before your break to book a flight from STL to PSE often results in higher prices. While it's possible to find some last-minute deals, they're not always guaranteed. Be flexible with your itinerary to maximize your chances of landing a bargain.
Is it cheaper to book a STL to PSE flight and hotel package?
Compared with arranging flights and hotels separately, booking a STL to PSE flight and hotel package with Expedia could result in significant savings. What's more, having everything in one convenient place takes the hassle out of travel planning. Just pick your flights and select from our extensive range of hotels, then tailor your trip with other add-ons like tours, car rentals and activities.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Mercedita Airport (PSE)?
Usually, it's possible to reschedule or cancel your STL to PSE flight. However, if the booking was made more than 24 hours ago, additional charges may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find further details on our Customer Service portal.

Travel information

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
Mercedita
Airlines serving
Frontier Airlines
Roundtrip price
$536
Distance
2023 mi

Book with confidence

Book with confidence

St. Louis to Ponce Flights

The cheapest times to fly from St. Louis to Ponce

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

 

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

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

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 Ponce in 2025. You can also book with separate airlines for your outbound and return journeys, from $153 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 Ponce 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 Ponce 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 Ponce Flights

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Explore a world of travel with Expedia

*Available to One Key members.