$120 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 8/8. 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

Sat, Aug 15 - Fri, Aug 28
Frontier Logo
4:09 pm - 1:20 pm
STL
-
SJU
20h 11m
1 stop
Frontier Logo
3:06 am - 12:14 am
SJU
-
STL
22h 08m
1 stop
$258Frontier
Tue, Aug 25 - Wed, Aug 26
Frontier Logo
4:10 pm - 1:54 am
STL
-
SJU
8h 44m
1 stop
Frontier Logo
6:25 am - 2:48 pm
SJU
-
STL
9h 23m
1 stop
$271Frontier
Tue, Aug 18 - Sun, Aug 23
Frontier Logo
4:10 pm - 1:54 am
STL
-
SJU
8h 44m
1 stop
Frontier Logo
4:05 pm - 12:14 am
SJU
-
STL
9h 09m
1 stop
$276Frontier
Thu, Aug 13 - Mon, Aug 17
Frontier Logo
4:09 pm - 2:11 am
STL
-
SJU
9h 02m
1 stop
Frontier Logo
3:06 am - 12:14 am
SJU
-
STL
22h 08m
1 stop
$303Frontier
Thu, Sep 3 - Tue, Sep 8
Frontier Logo
4:10 pm - 1:54 am
STL
-
SJU
8h 44m
1 stop
Frontier Logo
4:05 pm - 12:14 am
SJU
-
STL
9h 09m
1 stop
$321Frontier
Tue, Sep 29 - Tue, Oct 6
United Airlines Logo
9:23 am - 11:50 pm
STL
-
SJU
13h 27m
2 stops
United Airlines Logo
2:55 pm - 10:30 pm
SJU
-
STL
8h 35m
1 stop
$336United Airlines
Wed, Sep 2 - Wed, Sep 9
American Airlines Logo
6:03 am - 6:24 pm
STL
-
SJU
11h 21m
2 stops
American Airlines Logo
6:30 am - 1:22 pm
SJU
-
STL
7h 52m
1 stop
$341American Airlines
Fri, Jul 3 - Fri, Jul 10
Frontier Logo
4:17 pm - 2:09 am
STL
-
SJU
8h 52m
1 stop
Frontier Logo
6:31 pm - 11:59 pm
SJU
-
STL
6h 28m
1 stop
$348Frontier
Wed, Jul 1 - Wed, Jul 8
Frontier Logo
5:06 pm - 12:15 am
STL
-
SJU
54h 09m
2 stops
Frontier Logo
5:15 pm - 5:37 pm
SJU
-
STL
25h 22m
1 stop
$357Frontier
Fri, Jul 3 - Fri, Jul 10
Frontier Logo
5:06 pm - 2:34 pm
STL
-
SJU
44h 28m
2 stops
Frontier Logo
5:15 pm - 8:57 am
SJU
-
STL
16h 42m
1 stop
$360Frontier
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 $496 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 $496.

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

The average price for all round-trip flights from St. Louis to Puerto Rico depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to Puerto Rico is generally in the morning, when round-trip flights cost $626 on average. The most expensive time of day to fly to Puerto Rico is generally in the morning, which is peak travel time and where the average cost of a ticket is $626.

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 July, when tickets cost $101 (return) on average. On the other hand, the most expensive months are April and January, when the average cost of round-trip tickets is $193 and $182 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 1 week before departure. For the absolute cheapest price, our data suggests you should book 14 weeks before departure.

Good to know

Low seasonSeptember
Cheapest flight$120
Best time to beat the crowds with an average 47% drop in price.
Most popular time to fly and prices are also 4% 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.

  • How many flights are there between St. Louis and Puerto Rico per day?

    There is a maximum of 1 nonstop flight a day that takes off from St. Louis and lands in Puerto Rico, with an average flight time of 4h 25m. The most common departure time is 9:00 am and most flights take off in the morning. Each week, there are 1 flights.

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 4298 reviews
8.0Comfort
8.1Boarding
7.5Entertainment
7.0Food
8.6Crew
Airline reviews

I'm glad it wasn't only 75% full because I could get a good seat

8.0 ExcellentBobby, May 2026
BNA - GSP
Read more Southwest reviews

I'm glad it wasn't only 75% full because I could get a good seat

if I was good. Not happy that I have to pay extra money to get the seat I need for lake room, but I guess that’s a sign of the times.

Seats were very comfortable. They tilted back. Drinks and snacks were free and served 3 times. Attendants were awesome.

Plane was clean and comfortable. Flight attendants and gate staff were professional, friendly and efficient. Boarding and deplaning were orderly and efficient. All in all, the typical excellent Southwest experience.

Truly terrible. Will never willingly fly southwest again. Seats are worse than before they switched to assigned seating. One flight attendant was the opposite of helpful (rude, unhelpful, dismissive, and as my stranger seatmate said unprompted: a total prick). This caused me, 15 minutes into the flight, to book an alternate return flight home on a competing airline (first class 1.2k purchase instead of my existing planned flight) just so I would not have to ever be on that aircraft, with that terrible service person, with those horrific seats ever again.

Not having a five hour delay with little notice! The crew was very kind, though, and just as tired as we passengers were. The flight didn't depart until nearly 1 am...and no reason was ever given.

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

First time I've had to use the disabled accommodations. And I could not have had a better experience with Southwest, i was having trouble getting from one terminal to another due to my heart failure. And the next thing I know a Southwest agent had made sure. I had a wheelchair at all my flights. Can't thank them enough.

Delayed flight, lack of information, boarding process is a mess as is the carryon luggage causing issues when leaving the plane….just a poor experience.

Bus to plane was delayed for no apparent reason and our luggage was still on the belt when they shut it off. Took about 20 minutes to turn it back on to get our luggage.

It was a pleasant surprise to have complimentary Wi-Fi on the flight

Much better than Latam, the worse airline company ever. I hope I don't have the need to fly Latam ever in my life again.

Seats in Delta Main are unbelievably close to the seat in front of. Hard to get a backpack under the seat.

The flight was operated by Latam. The aircraft had a technical issue and the flight was delayed for the next day. They grounded other passengers to get their airplane assigned to my flight. Most of he ground staff don't speak English (Orlando Airport), but were very polite.The crew on the other hand could speak English and Portuguese. On board service was good.

The agent at check in and at the gate were less than thrilled to be at work. I'm not a fan of Kayak's placement on the plane. I got put in the middle seat and none of my preferences were used.

In ATL they have two sets of departure screens. Follow what is on your airline's departure board - the ATL Airport Authority departure board had completely incorrect details about the gate assignment for my flight, which would have made me miss boarding.

Flight was delayed it was hot while sitting on the plane, one engine was working on the plane until they had to do some jimmy rigging down the runway in order for the other engine to charge up. It was ridiculous

The flight was very good and the staff was very friendly and helpful!

The only thing I would say is we tried to get on a standby earlier flight, but with our fair we couldn’t. That seems senseless to leave with open seats..

WiFi didn’t exist , seats were super cramped, lights stayed on near my seat for a long time while others were dimmed, the food/trash/drink cart hit my shoulder at least a couple of times while moving, food options were down to just one option by the time it got to my row, the utensils were garbage (knife bent at a couple of places by the time I was done eating) the spoon was very flimsy plastic

Friendliest Flight Attendant I’ve seen since I flew on Southwest Airlines. The whole trip was outstanding…and arrived Early!

It was good overall except from Omaha to Denver when flight a was a repeatedly delayed apparently due to some issue at Denver. Communications could have been handled better. I had to board then deboard with luggage and board again

I didn’t have a seat assignment and my seat was very dirty on the flight from Frankfurt to Budapest.

Left an hour and a half after the listed time. Up side was it had TV screens on the seat.

No screens or meal options. Freezing cold. Dirty seats. Left late.

O’hsre taxi and deboarding took 40 minutes. Needed 20 minutes extra time between connecting flights to avoid running through terminal.

Cree was organized and pleasant. Plane had good seating but as it’s a shuttle toilets hadn’t been thoroughly cleaned (eg. bins too full)

I liked that my son and I were reseated next to each other (we had different bookings). I liked that it was a directg flight and mostly on time. I liked that you provided pillows and blankets. Flight attendants were generally courteous. The messaging through wifi did not work well. The food was not good. Seats are very narrow and I felt slightly claustraphobic in the window seat.

Overall a good experience, but no wifi available for free or for purchase and we got wet from condensation or other water source during descent.

We had several flights and they were all on-time and flawless

My Frequent Flyer nber wasn't put on as I was told it was..... This resulted in a last group boarding and no priority tags on My bags.

Premium Economy Good crew, good service, excellent food. Seat back screen just not bright enough.

Terrible steward... Plane was quite empty... I asked to move "back" in the plane and the steward said no... Unnecessary power trip of mediocre people.

Flight was delayed an no one cares, or try to help passengers to get the conexión.

Our flight was cancelled while we are on our way to the airport. So, no notice. We were rescheduled to another airline with a 2 hour later takeoff and so arrived at our destination on time. We pre-paid American Airlines $190 to upgrade our seats. No refund. So no use for AA or Kayak.

The small flights with Valet Luggage has a poor service

Terrible, horrible, disappointing- without telling us they changed planes and moved and separated our seats to opposite sides - said they changed seats putting us together - got to airport to find no, they did not - we sat opposing sides of plane - food overly salty to inedible, never saw stewardess but once - it was terrible

not sure why you ask about food, I n3ver get food on flights except maybe cookies or pretzels. wifi was slow and in and out most of the flight not good.

The crew was very attentive through out the flight. Seats were comfortable, nice flight bag with pillow and blanket. Food was okay, since it was a overnight flight seemed to go by fast.

The staff at the check in counter was so rude. Made you feel Incompetent

Frontier scheduled a 40 minute connection in DEN. What they failed to mention was that they “close the doors” 20 mins prior to departure, which means you only have 20 mins. Not enough time. Possibly against DOT regulations. Filing complaint.

Flight was scheduled at 9:40pm. Got delayed to 10 am, the next day. crazy

The bag check, flight check-in, and onboard experience convinced my wife and me that we will actively go out of our way to avoid flying Frontier Airlines in the future. At bag check, we were informed that check-in could only be completed via the Frontier mobile app. Unfortunately, the app was extremely frustrating—sending us through repetitive, confusing loops that repeatedly forced us to decline add-on services with nearly every click. While most airline apps upsell, this one felt intentionally exhausting. As the process dragged on, we became genuinely concerned that my phone battery would die before check-in could be completed. We approached the bag check staff—who were standing together talking—and explained both our frustration and our predicament. They laughed. Later, my wife described the interaction as “gaslighting,” which felt accurate. We were then informed it would cost $25 per person simply to have our boarding passes printed. From that point forward, the tone of the experience was consistently hostile. The bag check employees were condescending and combative, behaving more like bullies than customer service staff. Unfortunately, that same attitude continued onboard. One flight attendant argued with me when I attempted to stow my backpack in the overhead bin. I explained that we had each paid $75 to check our bags specifically so we would not need to use carry-on space and could have adequate legroom. She demanded to see my ticket, pointed out that it said “no carry-on”—which I acknowledged—and I reiterated that this was precisely why we paid to check our bags. Her response was, “I don’t make the rules.” She then walked away, but not before asking if I “truly wanted to fly back to Chicago today?”—an unnecessary and unmistakable threat. It is also worth noting that despite booking our tickets together in the same transaction, we were not seated together. Upon our return to Chicago—where we could once again sit together—we compared onboard experiences. We both remarked on how unhappy the flight attendants appeared and how each of us was separately asked whether we would like to purchase a beverage. We declined. At no point was water mentioned as an option, leaving us with the clear impression that even water came at a cost—or that complimentary water, if available at all, was deliberately left unmentioned. Overall, the experience was shocking and deeply disappointing, but it was also a profound learning experience—one we will not forget and will not repeat. -Steve

Plane was hot and miserable and the crew was rude!

12 hour delay required getting on and off plane 3 times - would have at least liked to have been offered a snack or drink

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

The crew acted like they had never done this and kept barking passive aggressive orders at people. + the security line + the delay + sitting on the tarmac for 2 hours + none of the apps or signage updating with correct times

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

Information on your arrival and departure airports