$120 Find Cheap Flights from Puerto Rico to St. Louis

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to St. Louis departing on 8/5. 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

KAYAK searches hundreds of travel sites at once for deals on flights to St. Louis

 
These are the airlines KAYAK users have selected most often from within our search results for flights to St. Louis, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results for flights to St. Louis, as well as popular online travel agencies
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Cheap Flights from Puerto Rico to St. Louis

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Puerto Rico to St. Louis 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 Puerto Rico to St. Louis

Thu, Aug 13 - Tue, Aug 25
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
Frontier Logo
3:33 pm - 4:55 am
STL
-
SJU
12h 22m
1 stop
$234Frontier
Thu, Aug 13 - Wed, Aug 26
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
Frontier Logo
4:10 pm - 8:09 am
STL
-
SJU
14h 59m
1 stop
$238Frontier
Thu, Aug 13 - Tue, Aug 25
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
Frontier Logo
4:10 pm - 1:54 am
STL
-
SJU
8h 44m
1 stop
$258Frontier
Fri, Aug 28 - Tue, Sep 1
Frontier Logo
6:16 pm - 12:14 am
SJU
-
STL
6h 58m
1 stop
Frontier Logo
3:33 pm - 4:55 am
STL
-
SJU
12h 22m
1 stop
$276Frontier
Thu, Jul 9 - Wed, Jul 15
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
Frontier Logo
4:09 pm - 7:57 am
STL
-
SJU
14h 48m
1 stop
$291Frontier
Thu, Aug 13 - Tue, Aug 25
Frontier Logo
5:15 pm - 8:57 am
SJU
-
STL
16h 42m
1 stop
Frontier Logo
6:33 pm - 12:44 am
STL
-
SJU
29h 11m
2 stops
$312Frontier
Fri, Jul 24 - Tue, Jul 28
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
Frontier Logo
4:09 pm - 2:11 am
STL
-
SJU
9h 02m
1 stop
$321Frontier
Wed, Aug 12 - Tue, Aug 25
Frontier Logo
3:06 am - 5:37 pm
SJU
-
STL
15h 31m
2 stops
Frontier Logo
6:33 pm - 5:36 pm
STL
-
SJU
22h 03m
2 stops
$323Frontier
Wed, Aug 12 - Wed, Aug 26
Frontier Logo
3:06 am - 5:37 pm
SJU
-
STL
15h 31m
2 stops
Frontier Logo
5:33 pm - 4:34 pm
STL
-
SJU
22h 01m
2 stops
$325Frontier
Fri, Sep 11 - Sun, Sep 13
Southwest Logo
8:55 pm - 7:40 am
SJU
-
STL
11h 45m
1 stop
Southwest Logo
6:20 am - 2:00 pm
STL
-
SJU
6h 40m
1 stop
$336Southwest
Booking Insights

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

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

What is the cheapest flight to St. Louis?

These are the best round-trip prices found by users searching on KAYAK in the last 72 hours.

In the last 3 days, the cheapest flight deal to St. Louis was found on the route from San Juan, at $234 return. The most popular connection is from New York to St. Louis and KAYAK users have found round-trip deals for as low as $296 in the last 3 days.

What is the cheapest day to fly to St. Louis?

The average price of all round-trip flights to St. Louis clicked on KAYAK for each day over the last 12 months.

Based on KAYAK data, the cheapest day to fly to St. Louis is Saturday where round-trip tickets can be as cheap as $696. On the other hand, the most expensive day to fly is Saturday, where round-trip prices are $696 on average.

What is the cheapest month to fly to St. Louis?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights to St. Louis, 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 to St. Louis is January, where tickets cost $248 on average for return flights. On the other hand, the most expensive months are June and July, where the average cost of tickets from Puerto Rico is $541 and $537 respectively. For one-way flights, the best month to travel is January with an average price of $248.

What is the cheapest time of day to fly to St. Louis?

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

The cheapest time of day to fly to St. Louis is generally in the evening, when round-trip flights cost $739 on average. The most expensive time of day to fly to St. Louis is generally in the evening, which is peak travel time and where the average cost of a ticket is $739.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights to St. Louis, 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, you should book around 2 weeks before departure, which saves you about 27% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$118
Best time to beat the crowds with an average 41% drop in price.
Most popular time to fly with an average 6% increase in price.
Flight from San Juan to St. Louis

FAQs - booking St. Louis flights

  • What is the cheapest flight to St. Louis?

    In the last 3 days, the cheapest flight deal to St. Louis was found on the route from San Juan, at $234 return. The most popular connection is from New York to St. Louis and KAYAK users have found round-trip deals for as low as $296 in the last 3 days.

  • How far is Lambert-St Louis Airport from central St. Louis?

    Lambert-St Louis Airport is 13 miles from the center of St. Louis.

  • What is the name of St. Louis’s airport?

    St. Louis is served by Lambert-St Louis Airport, also commonly referred to as Lambert Field, Lambert-St Louis, St. Louis Lambert, or St. Louis Lambert Intl. The airport code is STL.

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

    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 to St. Louis.

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

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

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

    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 to St. Louis 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 to St. Louis?

    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 to St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • How many direct flights to St. Louis are there each week?

    Each week there are around 3,228 direct flights from within Puerto Rico to St. Louis. The most common day for departures is Sunday, with 16% of flights taking off on this day.

Top tips for finding cheap flights to St. Louis

  • Enter your preferred departure airport and travel dates into the search form above to unlock the latest St. Louis flight deals.

Reviews of the top 4 airlines serving from Puerto Rico to St. Louis

 
See real verified KAYAK customer reviews for airlines flying to St. Louis. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline from Puerto Rico to St. Louis. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with to St. Louis? 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.
7.9
SouthwestOverall score based on 4305 reviews
7.5Entertainment
7.0Food
8.0Comfort
8.6Crew
8.1Boarding
Airline reviews

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.

2.0 MediocreJoshua, May 2026
TPA - LAS
Read more Southwest reviews

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.

Comfortable. Easy. No problems. Just wish they had gf options for snacks.

The crew was very kind and made going to Hawaii relaxing and fun to look forward to! Thank you Southwest for a pleasant flight!

This leg was much better, but we did have to have a 3 hour lay o er after coming from a very exhausting hiccup with our flight from BNA to Den

We waited in the airplane for over 45 min for a southwest employee to make the flight. This cause over half the plane to miss their connecting flight in Denver. When we confronted the desk upon arrival, they told us the only flight they had was the next day leaving at 8:50 pm!!! Or they offered to get us to Burbank or LA, but after that we were on our own to get back to Santa Barbara. I paid for a flight from sba to bna bna to sba. My re entry into mom mode has been 💯 rough because of southwest mistake with my flight. And now I’m leaving to Reno tomorrow for a vballl tournament and just discovered that my leg in Vegas has me and my 3 kids on a stand by flight even though I had booked these ticket last year November!! Do better southwest!

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.

Everything could and should be better. We are paying for, it's not a favor, it's a service and should involve quality, responsibility and respect.

Seats were comfortable, 8 hours. One flight attendant was not appropriate in his verbal response: "Please, DON'T touch me.", after being tapped near his elbow after being made unaware he skipped serving me & had passed further down the aisle.

Boarding in Amsterdam is always chaotic. More complicated than needs to be ( boarding pass checked twice, once for general security, then by the airline). The bathrooms on this flight are dirty, and smelly. The food was mediocre at best The crew was decent

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

Round trip flight to Canada and back to the US was smooth and efficient.

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.

Spanish speaker flight attendants were incredibly rude. A male flight attendant named Allen, grabbed my bag out of the overhead bin and moved it without my permission. When I asked what he was doing, he informed me that the overhead bins were public space? It would be easy to ignore this comment, as you don’t know the whole story, but the flight attendants were militant and rude. Delta, you can do better!

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

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.

Everything was fine except the end of the flight. We spent more than an hour circling around Miami due to weather conditions. That was not good.

They lost my bag. ... And I asked them 3 times to 3 different people if my checked bag will maKe it all the way - they all confirmed and at the end it was left at the connection... Bravo

Cancelled BOYH legs of our flight home 30 min before initial boarding

Cancelled the flight half hour before boarding. Then cancelled the connecting flight too.

Delayed due to weather in Dallas (arriving flight arrived late), then boarded the plane only to deboard immediately afterwards, tire needed to be replaced. Flight supposed to depart at 6:15pm but departed at 9:35pm.

Left early arrived early..right amount of talking from pilots..of course had to love the biscuit and water!

I would like a refund for the extra cost the seat I paid for. An oversized person sat next to me and I couldn’t fit on my seat and had to move to another seat.

Boarding gate at LAX was too crowded—two gates next to one another

The flight was delayed about an hour for a maintenance specialist to approve the maintenance repair

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

Zero issues with this flight. Crew was outstanding and flight was super. Plane was clean and fine. The seats need more padding and water should be provided without cost. I recognize it's Frontier but there are some things that should still be part of the flight. But still very satisfied with the experience and quality.

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

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Everything you need to know for your flight to St. Louis

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