$100 Find Cheap Flights from St. Louis to Puerto Rico

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Puerto Rico departing on 3/17. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Book Cheap St. Louis to Puerto Rico Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Puerto Rico that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from St. Louis to Puerto Rico

Tue, Mar 24 - Tue, Apr 14
Frontier Logo
4:51 pm - 8:54 am
STL
-
SJU
15h 03m
1 stop
Frontier Logo
3:08 am - 11:19 pm
SJU
-
STL
21h 11m
1 stop
$202Frontier
Sun, May 3 - Wed, May 6
Frontier Logo
4:59 pm - 9:54 am
STL
-
SJU
15h 55m
1 stop
Frontier Logo
6:30 am - 11:19 pm
SJU
-
STL
17h 49m
1 stop
$213Frontier
Sat, May 9 - Tue, May 12
Frontier Logo
4:55 pm - 2:01 am
STL
-
SJU
8h 06m
1 stop
Frontier Logo
3:08 am - 11:19 pm
SJU
-
STL
21h 11m
1 stop
$221Frontier
Sun, Apr 26 - Thu, Apr 30
American Airlines Logo
6:29 am - 2:29 pm
STL
-
SJU
7h 00m
1 stop
American Airlines Logo
1:31 pm - 10:24 pm
SJU
-
STL
9h 53m
1 stop
$222American Airlines
Wed, Apr 8 - Sun, Apr 12
Frontier Logo
4:59 pm - 2:01 am
STL
-
SJU
8h 02m
1 stop
Frontier Logo
5:25 am - 7:51 am
SJU
-
STL
27h 26m
1 stop
$223Frontier
Mon, Apr 13 - Thu, Apr 16
Frontier Logo
4:59 pm - 10:48 pm
STL
-
SJU
28h 49m
1 stop
Frontier Logo
3:21 am - 11:19 pm
SJU
-
STL
20h 58m
1 stop
$228Frontier
Sat, May 9 - Wed, May 13
Southwest Logo
5:40 am - 1:20 pm
STL
-
SJU
6h 40m
1 stop
Southwest Logo
5:35 am - 1:25 pm
SJU
-
STL
8h 50m
2 stops
$232Southwest
Tue, Mar 31 - Tue, Apr 7
Frontier Logo
11:27 am - 12:57 am
STL
-
SJU
12h 30m
1 stop
Frontier Logo
6:30 am - 11:25 pm
SJU
-
STL
17h 55m
1 stop
$234Frontier
Tue, May 12 - Sat, May 16
Delta Logo
1:27 pm - 8:30 pm
STL
-
SJU
6h 03m
1 stop
Delta Logo
4:10 pm - 11:21 pm
SJU
-
STL
8h 11m
1 stop
$236Delta
Fri, Mar 27 - Fri, Apr 10
Frontier Logo
4:51 pm - 2:03 am
STL
-
SJU
8h 12m
1 stop
Frontier Logo
9:10 pm - 7:51 am
SJU
-
STL
11h 41m
1 stop
$239Frontier
Booking Insights

KAYAK's insights & trends for St. Louis to Puerto Rico flights

Get data-powered insights and trends into flights from St. Louis to Puerto Rico to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest St. Louis to Puerto Rico flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Puerto Rico from St. Louis found in the last 72 hours was to San Juan, at $526 round-trip. The most popular route is from St. Louis (STL) to San Juan Luis Munoz Marin Intl Airport (SJU), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $526.

What is the cheapest month to fly from St. Louis to Puerto Rico?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Puerto Rico, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from St. Louis to Puerto Rico is September, when tickets cost $219 (return) on average. On the other hand, the most expensive months are December and July, when the average cost of round-trip tickets is $615 and $543 respectively.

How far in advance should I book a flight from St. Louis to Puerto Rico?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Puerto Rico, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from St. Louis to Puerto Rico, you should book around 3 weeks before departure, which saves you about 18% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 19 weeks before departure.

Good to know

Low seasonSeptember
Cheapest flight$100
Best time to beat the crowds with an average 50% drop in price.
Most popular time to fly and prices are also 9% lower on average.
Flight from St. Louis to San Juan

FAQs - booking Puerto Rico flights

  • From St. Louis, can I fly to the South Coast of Puerto Rico?

    Yes. You can book a flight through KAYAK from STL to the city Ponce, which is located on the southern coast of Puerto Rico. You will be landing at the Mercedita International Airport (PSE). Spirit is one carrier that offers a flight from STL to PSE with one stop, usually in Orlando. Airlines such as Spirit, Cape Air, and JetBlue offer flights from STL to PSE with two stops. Layover cities often include Orlando, Baltimore, Nashville, and other cities.

  • Where can I go in Puerto Rico for a remote tropical vacation?

    You can fly from St. Louis to the Isla Day Culebra, a small island that is part of Puerto Rico but located to the east of the main island. When you fly to this small island, you will be landing at the Aeropuerto Benjamín Rivera Noriega (CPX). Frontier, Spirit, Cape Air, Silver Airways, and United are among the airlines that offer two- or three-stop flights from STL to CPX. Layover destinations include Washington DC, Dallas, Orlando, and others.

  • What is the San Juan Airport like?

    The San Juan Airport on the northern coast of Puerto Rico is the busiest airport in the Caribbean. This four-terminal airport includes a hotel at the airport, exclusive lounges you can access by paying at the door, shops and restaurants that usually close at night, a currency exchange, public transportation, rental cars, and more.

  • Does STL have private facilities for nursing mothers?

    Yes. STL offers lactation suites throughout the airport at Gates A10, C9, and E33. Each lactation suite is a clean, calm, quiet space where a nursing mom can breastfeed in private or where she can go to pump. Each suite features comfortable seating, a table, an ottoman, a bench, a sink, and an electrical outlet.

  • How does KAYAK find such low prices on flights from St. Louis to Puerto Rico?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Puerto Rico.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Puerto Rico?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from St. Louis to Puerto Rico is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Puerto Rico?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from St. Louis to Puerto Rico with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Puerto Rico?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from St. Louis to Puerto Rico up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Puerto Rico?

    The cheapest time of day to fly to Puerto Rico is generally in the morning, when round-trip flights cost $646 on average. The most expensive time of day to fly to Puerto Rico is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $710.

Top tips for finding cheap flights to Puerto Rico

  • The St. Louis Lambert International Airport (STL) is a hub for Air Choice One and Cape Air. When you book your flight through KAYAK for St. Louis to Puerto Rico, you will have many options of destination, airline, flight time, and price.
  • When you fly from STL to San Juan, the capital of Puerto Rico, you'll be landing on the northeast of the island at the Luis Muñoz Marín International Airport (SJU). Airlines such as Spirit, Frontier, Delta, and United are among the carriers that offer one-stop flights from STL to SJU. Common layover cities include Atlanta, Orlando, and Charlotte. United and American are among the airlines that offer flights from STL to SJU with two stops.
  • If you're flying from STL to Aguadilla, the beach town in the northwest of Puerto Rico, you'll be landing at Rafael Hernández Marín International Airport (BQN). Frontier and Spirit are among the airlines that offer one- and two-stop flights from STL to BQN, with layovers in cities such as Orlando, Tampa, Las Vegas, and Fort Lauderdale.
  • As you wait for your flight to Puerto Rico at the St. Louis International Airport, you can enjoy the live music of a piano player in the terminal. STL decided to have the piano player as part of an arts and culture initiative at the airport, a program designed to delight travelers and enhance their experience.
  • The St. Louis Airport has two interfaith chapels that welcome all. These quiet spaces are meant for reflection, meditation, prayer, or simply for relaxation. These chapels are open 24/7. One chapel is located on the lower level of Terminal 1 and the other is near Gate E40.

Reviews of the top 5 airlines serving from St. Louis to Puerto Rico

 
Need help choosing which airline to fly with from St. Louis to Puerto Rico? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4311 reviews
8.0Comfort
7.0Food
8.1Boarding
7.5Entertainment
8.6Crew
Airline reviews

I realize they are still working out kinks with the new boarding process, but by the time I boarded in group 5, most of the bins were full. All airlines should better enforce small bags and jackets going under the seats until everyone has boarded.

8.0 ExcellentAnonymous, Mar 2026
MCO - IND
Read more Southwest reviews

I realize they are still working out kinks with the new boarding process, but by the time I boarded in group 5, most of the bins were full. All airlines should better enforce small bags and jackets going under the seats until everyone has boarded.

WiFi was not working and didn’t have a beverage service

Snacks are always pretzels. Why can't you also offer peanuts ?

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

Mediocre. Boarding is now unpleasant. The employees, once friendly and nice, are now regularly speaking sternly to passengers, badgering them to do things right so they can take off on time and gate check bags because they don't have enough overhead bin space. The pretzel snack was crushed flat and broken into even smaller pieces, which happens frequently lately. Drink service was suspended before they reached my row.

The last 3 flights between BWI and BDL canceled the beverage service mid- way. Just say up front that the fight is too short. Thanks!

It was canceled. Supposedly weather. But there was no snow in Baltimore. At least we found out before driving to airport

I have not flown Southwest in awhile and had a very pleasant experience. From ticketing to boarding to the flight. The flight left on time and landed ahead of schedule. It won't be so long next time!!

The Southwest experience has definitely taken a dive from its early days. You can no longer deferentiate from other airlines. Air travel is too expensive. Southwest is no longer budget friendly. They have lost me as a loyal customer.

Flight was hours late, unable to sit next to spouse, I have had so much better experiences. Substantially better, only saving grace was that it was a short flight.

Could not get my connecting flight boarding pass until four hrs before departure! Ver annoying especially since the staff could not explain why!

The flight was flying with 30% capacity. The flight my seat from preferred seating to back of the seat. Even though i can understand that this was to balance the flight weight. The flight attendance decided to do the serving near my seat and in the middle , their noices woke me up from sleep , when i realized that the service has ended and when they were going back asked for a coffee, for which they answered they have completed teh service in my location. That really upset me as they woke me up and also rejected the coffee i asked. I ended up landing with a headache, thanks to the crew that screwed up my travel

Delayed. Hot. Passenger next to me was so large I couldn’t move.

Same experience as the flight from Norfolk to Atlanta where people are boarded in zones that don't make sense. People behind you on the plane will get on before you and they take the luggage space on your row.

The boarding process doesn't make sense since some people that will sit behind your rows are boarded before you and then they take up the luggage space above your head. I then have to wait for people to get off the plane before I can go back to get my luggage.

Good flight. Connector flight was delayed so made a short turnaround in Atlanta which was stressful. Otherwise, great crew, Staff in ATL was very informative about the delay and ensured people their connections were fine. Notified the ones that were not. Great communication.

The flight went very well, but the flight attendants didn't serve and food or drinks other than 1st class due to rough air but to be honest it wasn't that bumpy and I felt that they could've at least offered water and coffee perhaps. Also serving 1st class only is a bad look. I've been in 1st class many times and I would've felt that if the turbulence was too rough for the main cabin, it would be too rough for 1st class too.

There was an unruly family behind us that made the short flight miserable!!! The cabin crew did nothing to contain it.

My seatback screen didn’t work so that sucked because that’s what I was going to do on the plane.

Left a few minutes early. Got in 15 minutes early. Very attentive service on board. Very organized boarding.

The travel company that you have on your site did me so wrong. I don’t know how it happened, but they put my son‘s name on my plane ticket flying to Vietnam. Along with his birthday. They would not have let me fly from Fort Myers to Ho Chi Minh City. I don’t think that I can ever use your service again. I typed my information into the browser along with my passport number and four days before I’m leaving I have to quickly search another ticket to fly out here.

Seats are uncomfortable. This has been a trend in the industry for decades. Trying to fit more seats on each plane to increase profits at the expense of the passenger.

The flight was delayed so we were dead tired, and after that the turbulence was horrible. I was very scared.

It’s always a great time flying with united airlines.

Good flight. Efficient boarding and competent flight crew. No problems until we arrived at our destination gate. We were early so there was an aircraft at the gate that had to move before we could pull in. Then, due to the type of aircraft we flew, the cabin door could not be opened until some luggage from the cargo bay was offloaded to preserve center of gravity characteristics. So, that further delayed deplaning. Despite being 20 minutes early on landing, we ended up being 5 to 10 minutes late after all the delays.

Everything went well except the turbulence what no one have a control of but pilot and crew handled very good!

There was no WiFi available, there were mechanical problems with the plane and we landed at C 124, then the gate was switched to A 26, then all the way back to C126! For a 75 yo woman traveling alone, this was a difficult journey, indeed!

This trip did not start off well. The inbound flight was delayed about 20 minutes. Then, after initial onboarding, the passengers had to deplane due to a mechanical problem. That took about 30 minutes to fix and be cleared. Then, reboarding was chaotic. It took a long time to sort passengers and two passengers on standby were ticketed but there was no seat. So, they had to deplane. One of the flight crew was trying to help passengers figure out a place to put their carry-on bags and that took more time. In the end, our scheduled 10:30 am departure did not actually take off until about 12:05 pm CST. The flight itself was long but we got to Houston. Some passengers missed their connecting flights and had to rebook. Not the best of flights I've had.

Staff were good. My seat was in need of repair, but for a short flight was not problematic. Usual basic snack and drink setup that you'll find on any US carrier. Over, a decent, basic flight.

Complimentary light meal would be appreciated. But great flight crew service on all legs

Plane from partner PSA was filthy. Plastic needs to be thoroughly cleaned. Really disgusting to look at and wonder about cleanliness of parts less visible.

The baggage claim experience was poor. The plane crew and the AA app said that checked baggage in CLT would be at carousel 7 but the sign at Baggage Claim said carousel 1. The carousel 1 sign had the correct flight # listed above the belt. But the luggage never came. I went to an AA baggage claim office after about 1 hour and the clerk directed me to another AA room that was poorly marked, with a closed door and no obvious way to know what to do. Finally someone opened the door and my bag was inside. The clerk was totally unable to explain why.

They are rarely on time! Very hard to plan your travels when flights or connections keep getting delayed.

Flight delay for mechanical. Inbound arrived on time. No one said why mechanical delay.

Forced to check bags. Crew uninterested in collecting trash. Unclean seats.

why would I bother with this airline and pick seats when I am asked to move for a weight imbalance

Flight pulled out on time but sat on runway for 30 mins. It was extremely cold in the aircraft despite wearing a winter coat. Surprisingly they had a vegetarian meal but could have some better snack choices for a 8 hour flight.

We had a male flight attendant who was super attentive and wonderful! Very professional. I have both gluten and dairy intolerance, and was only able to get a gluten free part, and not the dairy free part of the meal. Easy to order ahead of time and I appreciate being able to do that.

Snow delayed boarding several times, which I understand happens. Issue I had was that after we did board, pilot told us we were going to roll out to be de-iced, then on our way. We were de-iced once, taxied to the tarmac and then stopped. Sat for another 30 minutes or so, the another de-icing. Then we rolled out to a parking spot, only to sit for another hour due to a traffic stop in DCA, which I'm confident they knew would happen before we boarded. Pilot gave no updates other than we had to hold, attendants did speak to the crew, but when asked, said the pilot would be updating us. We on the ground in the plane waiting for over 2 hours. They did communicate that bathrooms would be open, but no other news until we left. Would have been better to be up front about status.

Good crew and flight was on time. It’s a small plane with limited overhead luggage space. They said the overhead space was full and I had to check my bag. There was still space when I got on. Waiting for my checked luggage added 30 minutes to my trip. Not the end of the world but also not great.

The flight never took off and we spent 7 hours at the airport

Gate not determined until I got to the airport - hard to plan the trip to the airport.

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

Frontier.. nickel and dime add-ons. Flight late, on time, late again, last minute gate change, arrival gate required a shuttle to the terminal. They sure keep you guessing.. if you like a little chaos and airport anxiety, this is the airline for you!

This is my second time flying with Frontier. My current experience was very favorable. The staff from the gate to the plane was friendly, warm and professional. The food options lacked in my opinion. This area needs some attention in my opinion.

First of all we hade waited 3 hours in the airplane waiting to leave. Second the return schedule was changed and it messed up my entire vaction. I won't buy never again another flight and recommend to nobody traveling with them.

There was no food and no entertainment, so I'm not sure why these are even in the survey, as my understanding is frontier does not ever offer food without a few, not even a snack, and there are no screens so unless the flight safety talk is our entertainment why ask how we liked it?. One of the flight attendants say in the back of the plane as people filed in to their seats, yelling orders about where to put baggage and telling people to hurry up. It was the least professional experience I've ever had on a flight.

Very well recently! Frontier is improving and less harrassing customer on luggages! Positive!

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

I am writing to express my disappointment with my recent Frontier Airlines flight. I was charged $99 at the gate because my bag was said to be too large, yet once onboard there was no available overhead bin space, and I was required to place the bag under the seat in front of me anyway. This made the charge feel unnecessary and unfair. Additionally, before the flight even took off, I was asked to move from the seat I paid for into a middle seat so another passenger and her cat could have my seat to themselves. I was not offered compensation or an explanation for being moved from a paid seat. Between the unexpected bag fee and being forced to give up my seat, this experience fell well below acceptable customer service standards. I would appreciate a review of this situation and appropriate compensation.

Everything you need to know for your flight from St. Louis to Puerto Rico

Information on your arrival and departure airports