STL - SJU

$58 Find Cheap Flights from St. Louis to San Juan

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 San Juan departing on 2/10. 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 San Juan Luis Munoz Marin Intl Airport

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to San Juan.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to San Juan.
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41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest round-trip
$172
Typical prices: $301-$609
Frontier
Sat 1/31Wed 2/11
STL - SJU • 1 stop
Cheapest non-stop
$1,206
Southwest
Sat 3/21Sat 3/28
STL - SJU • Non-stop
Our travelers' advice
AI-powered summary based on content written by travel experts. AI can make mistakes.
Avoid peak hours at STL for shorter wait times.
For quick access to San Juan, taxis or Uber are best.
Expert advice
Expert advice
Expert advice
Expert advice
When to book
3 weeks
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 23% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
September
Cheapest • 51% price drop
March
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Nonstop flights
1 day a week
There are direct flights from St. Louis to San Juan 1 day a week: Sat.
Direct flights
Direct flights
Direct flights
Direct flights
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to San Juan!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from St. Louis to San Juan (STL-SJU)

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

Sat, Jan 31 - Wed, Feb 11
Frontier Logo
5:42 pm - 9:54 am
STL
-
SJU
14h 12m1 stop
Frontier Logo
5:25 pm - 10:27 pm
SJU
-
STL
7h 02m1 stop
$172Frontier
Sat, Jan 31 - Sat, Feb 7
Frontier Logo
5:42 pm - 9:54 am
STL
-
SJU
14h 12m1 stop
Frontier Logo
8:00 am - 8:04 am
SJU
-
STL
26h 04m1 stop
$176Frontier
Sat, Jan 24 - Sat, Jan 31
Frontier Logo
5:42 pm - 9:54 am
STL
-
SJU
14h 12m1 stop
Frontier Logo
8:00 am - 11:33 pm
SJU
-
STL
17h 33m1 stop
$177Frontier
Thu, Jan 8 - Mon, Jan 12
Frontier Logo
3:43 pm - 12:05 am
STL
-
SJU
6h 22m1 stop
Frontier Logo
9:23 pm - 10:34 pm
SJU
-
STL
27h 11m1 stop
$180Frontier
Thu, Jan 29 - Mon, Feb 2
Frontier Logo
5:42 pm - 3:26 pm
STL
-
SJU
19h 44m1 stop
Frontier Logo
8:00 am - 11:33 pm
SJU
-
STL
17h 33m1 stop
$181Frontier
Sun, Jan 11 - Wed, Jan 14
Frontier Logo
3:43 pm - 12:31 am
STL
-
SJU
6h 48m1 stop
Frontier Logo
7:34 pm - 10:34 pm
SJU
-
STL
29h 00m1 stop
$183Frontier
Sat, Jan 24 - Mon, Feb 2
Frontier Logo
5:42 pm - 9:54 am
STL
-
SJU
14h 12m1 stop
Frontier Logo
8:00 am - 11:33 pm
SJU
-
STL
17h 33m1 stop
$197Frontier
Wed, Mar 4 - Tue, Mar 10
Frontier Logo
3:49 pm - 12:43 am
STL
-
SJU
6h 54m1 stop
Frontier Logo
11:07 am - 11:19 pm
SJU
-
STL
13h 12m1 stop
$199Frontier
Sat, Jan 10 - Fri, Jan 16
Frontier Logo
5:11 pm - 1:49 pm
STL
-
SJU
18h 38m1 stop
Frontier Logo
3:58 am - 10:34 pm
SJU
-
STL
20h 36m1 stop
$200Frontier
Wed, Jan 7 - Wed, Feb 4
Frontier Logo
5:11 pm - 2:50 am
STL
-
SJU
7h 39m1 stop
Frontier Logo
4:36 pm - 11:33 pm
SJU
-
STL
8h 57m1 stop
$201Frontier
Booking Insights

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

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

How much is a round-trip flight from St. Louis to San Juan Luis Munoz Marin Intl Airport?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from St. Louis to San Juan Luis Munoz Marin Intl Airport departing in January.

What’s the cheapest day of the week to fly from St. Louis to San Juan?

The average price of all round-trip flights from St. Louis to San Juan Luis Munoz Marin Intl Airport clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from St. Louis to San Juan, look for departures on Wednesdays and avoid leaving on a Saturday, as it's usually the priciest day. When flying back from San Juan, Tuesday is the cheapest day to fly and Saturday is the most expensive.

What is the cheapest month to fly from St. Louis to San Juan Luis Munoz Marin Intl Airport?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to San Juan Luis Munoz Marin Intl Airport, 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 San Juan Luis Munoz Marin Intl Airport is September, where tickets cost $219 (return) on average. On the other hand, the most expensive months are December and July, where the average cost of round-trip tickets is $640 and $526 respectively.

How far in advance should I book a flight from St. Louis to San Juan Luis Munoz Marin Intl Airport?

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 San Juan Luis Munoz Marin Intl Airport, 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 San Juan Luis Munoz Marin Intl Airport, you should book around 3 weeks before departure, which saves you about 23% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Expert advice

Expert advice for your flight from St. Louis to San Juan

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airports
STL

Avoid peak hours at STL to minimize wait times. Early mornings and afternoons are busiest, so plan your departure accordingly.

SJU

For quick access to San Juan, taxis or Uber are best. They offer a short ride into town, avoiding parking hassles.

Our travel experts
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia Denisyuk

Yulia Denisyuk

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Read more
Gabriel Leigh

Gabriel Leigh

Expert on SJU

Gabriel Leigh

Gabriel Leigh

Gabriel is a writer and video creator. As senior content producer for Flightradar24 and Monocle’s transport correspondent, he keeps a close eye on aviation in particular. He has also written travel articles for the likes of The New York Times. Born in New York but raised around the world, he now lives in Sweden. He’s been to 75 countries, flying 2.3 million miles on 113 airlines and through 234 airports in the process.

Read more

Good to know

Low seasonSeptember
Cheapest flight$58
Best time to beat the crowds with an average 52% drop in price.
Most popular time to fly and prices are also 10% lower on average.
Flight from St. Louis to San Juan

When to book flights from St. Louis to San Juan

Are your dates flexible? Find out the best times to travel from St. Louis to San Juan based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking St. Louis to San Juan flights

  • What is the cheapest flight from St. Louis to San Juan Luis Munoz Marin Intl Airport?

    In the last 3 days, the lowest price for a flight from St. Louis to San Juan Luis Munoz Marin Intl Airport was $58 for a one-way ticket and $172 for a round-trip.

  • Do I need a passport to fly between St. Louis and San Juan?

    Yes, you'll most likely have to show a valid passport before boarding the plane in St. Louis and on arrival in San Juan.

  • Which aircraft models fly most regularly from St. Louis to San Juan?

    The Boeing 737 MAX 8 is the aircraft model that flies most regularly on the St. Louis to San Juan flight route.

  • Which airline alliances offer flights from St. Louis to San Juan?

    Star Alliance, SkyTeam, and oneworld are the airline alliances operating flights between St. Louis and San Juan, with Star Alliance being the most commonly used for this route.

  • On which days can I fly direct from St. Louis to San Juan?

    You can catch a nonstop flight from St. Louis to San Juan on Saturday.

  • Which is the best airline for flights from St. Louis to San Juan, Delta or Southwest?

    The two airlines most popular with KAYAK users for flights from St. Louis to San Juan are Delta and Southwest. With an average price for the route of $395 and an overall rating of 7.9, Delta is the most popular choice. Southwest is also a great choice for the route, with an average price of $584 and an overall rating of 7.9.

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

    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 San Juan.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to San Juan from 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 from St. Louis to San Juan?

    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 San Juan with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and SJU can sometimes prove cheaper using this method.

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

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

Prefer to fly direct from St. Louis to San Juan?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Lambert-St Louis to San Juan Luis Munoz Marin Intl.
Find which airlines fly direct from Lambert-St Louis Airport to San Juan Luis Munoz Marin Intl Airport, which days they fly and book direct flights.

Direct departures

Lambert-St Louis to San Juan Luis Munoz Marin Intl

Saturday

Southwest

Southwest

See more direct flights

Direct returns

San Juan Luis Munoz Marin Intl to Lambert-St Louis

Saturday

Southwest

Southwest

See more direct flights

Reviews of the top 5 airlines serving from St. Louis to San Juan

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to San Juan. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to San Juan? 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 4250 reviews
7.0Food
8.0Comfort
7.5Entertainment
8.1Boarding
8.6Crew
Airline reviews

They sent a notice that they were boarding an hour early. We had to leave the club and run to the gate. They said sorry, that came from corporate and was a mistake. They did not have enough seating because the flight before it had not taken off on time. They moved our gate and delayed it for an hour.

2.0 MediocreRobert, Dec 2025
LAS - TPA
Read more Southwest reviews

They sent a notice that they were boarding an hour early. We had to leave the club and run to the gate. They said sorry, that came from corporate and was a mistake. They did not have enough seating because the flight before it had not taken off on time. They moved our gate and delayed it for an hour.

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

Still a fan of open seating. Flight was on schedule and arrived on time. The 737 MAX is very comfortable.

Airline travel is always too cramped to really be pleasant, but the cabin crew on this flight did a pretty good job of making up for it by putting on some music during boarding and sprinkling a few funny remarks into the safety briefing and announcements, and just generally being friendly and helpful. It definitely reminded me of why I prefer the in-flight experience on Southwest!

No delays and arrived to destination 30 min early. Staff was super friendly.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

Had to get off plane from prior flight even though I had to reboard same plane to continue to my final destination.

I noticed that the planes seem to be outdated. There was no entertainment per se. Also, the waiting area did not have any working electrical outlets

None of the airplane features were available during the flight.

Original flight was cancelled and when i was rebooked by the airline, they couldn't seat me in the same type of seat as I had originally booked (went from window/aisle to middle/middle and one was a bulkhead seat, and other wasn't in the same class)

Lady Pilot was perfect in every way wheels up to wheels down communication, professionalism, excellent on time departure and on time arrival, excellent communication! Fantastic job with Superb attitude!!

The food is terrible. The staff is wonderful. Comfort is good.

Left on time, a bit delayed due to headwinds most of the trip.

I fly Delta all the time, have Platinum Medallion status. But this route seems to have major problems with delays and seems to never leave on time! Have only taken it twice in the last two weeks, and each time it had delays of more than 1 hour... very disappointed!!!!

Getting to the flight was arduous and lengthy. The flight itself was good but the food option wasn’t a good selection. I need to do a Kosher option on my return. Flight crew were nice

Good seats in Main cabin, excellent service and excellent landing

My flight was cancelled with no explanation after I had already cleared security. I was given 4 options to rebook, only one being non-stop like I had paid for. I grabbed it. It was 4 plus hours later and then took off even later. Biggest complaint is that I booked early and had an aisle seat. They gave me a "window" seat in front of the exit row, so the seat did not decline. I weigh all of 103 #s and it was tight for me! For what I paid, I feel I was kind of ripped off. I think they should have given me the empty comfort seat for the inconvenience. There was no apology nor any explanation as to why the flight was cancelled. My guess is it benefitted Delta in some way.

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

United overall experience is great these days. Airport experience was very organized. Staff on flight were great. App and information as good as it gets.

United have really come back. Airport and boarding process is clear and good, app and information also very good

They charged a fee for 1st bag checked. Others in same party were free.

Flight was delayed 8 times. We were sitting at the airport for 14 hours. We got 2 hours of sleep (if that) on what was not meant to be a red-eye.

The movies offered were great. Staff were very pleasant and very efficient.

After a delay at the gate, C3, at Ohare on Sunday, I left my Blk ski coat on the bench at the gate, lost! Please review my lob claim, thx.

Very bad! They kept delaying my flight and wouldn’t do anything about it

Did not understand a single word the attendant said on the pa system. I was glad it was not an emergency.

Flight was late and boarding was confusing because gate changed and I didn’t get a notification

Gate was overcrowded. Gate agents performed very well. Flight crew was top notch! Efficient & professional & courteous. Both meals not thermalized well. Dinner main dish was actually cold in the center. Almost inedible. Breakfast sandwich was lukewarm.

The boarding was as always, the crew tried their best but not enough. The food was a disaster I had dietary restrictions that were half met because the company did not loaded the food for the flight. The entertainment screen was fine but content was not and also they removed the free messaging option from the flight and they charged 30 dollars for that crappy bandwidth. This flight is not worth the cost and the company is going down on quality.

Not comparable to Qatar Airways services on flights to Doha. Flight attendants provided basic services; I was never recognized by name or as an Executive Platinum member. Restrooms were not kept clean during the flight.

Awful. They won’t help me with anything. I booked on American but they abdicated to Iberia. The ticket was overpriced. Everything negative

it was fine, decent flight... dont get food besides cookies or pretzels so not sure why you ask about food. same for entertainment..

I got sick nothing contagious but distressing and the care I received by Kayla? Keighly the flight attendant will be memorable for ever. Thank You

I got sick nothing contagious but distressing enough and the care I received on the flight was astounding.

Waaay too small plane. They also need to up the size of the overhead bins. I would love to keep me 3k with of camera equipment in my hard case baggahe instead of it being thrown into the belly of the plane

Not clean and was told I would get a great seat and it was not great at all

Flight got delayed for 5 hours no good explanation was offered ;(

Horrible. I would never fly Frontier again. The booking process is tricky at best, but fraudulent in my opinion. Frontier customer service did nothing to rectify my purchase -- I ended up paying more than double what I could have gotten from other airlines and nearly triple what I thought I was buying from Frontier. Their booking practices are unfair to the consumer.

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

Better than expected. Staff were friendly and nice on both flights.

There was no one at the counter to assist with our check in. The app didn’t work, so I arrived at the airport with time to check in and I couldn’t because no employees were there. When I finally got someone on the phone, it was inside the 60min rule and they said I could no longer check in and they could sell me another ticket. We had to scramble and pay an additional $800 for tickets and THEN AFTER (about 60 min from my original convo with customer service and 10min after original departure time) I had boarded my new flight, there was email saying my original flight from Frontier was delayed and leaving 2hr 50min later, but I STILL wouldn’t have been able to check in. Which means customer service should have been able to see it and let me check in because I was well within my check in time. When I call Frontier, they hang up on me. So their app didn’t work and they employees left and they take zero responsibility or assistance with their “customer service”

Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.

No fault of Frontier staff: plane was very late, reached Orlando at 1 am, took a while to get luggage. Weather, gov financial shutdown impact on TSA, air controllers seemed to have multiple flights backed up. Frontier staff seemed to cope as gracefully as possible. It did reassure me that I and my new hip could adapt to travel challenges. Food/entertainment were irrelevant to my trip.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

Everything you need to know for your flight from St. Louis to San Juan

Information on your arrival and departure airports