San Juan

$88+ Cheap flights from St. Louis (STL) to San Juan

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/16. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SJU
May 28 — Jun 41
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Cheap flight deals from St. Louis to San Juan

Cheapest flights from St. Louis to San Juan
Explore the most affordable flight options available from St. Louis to San Juan. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 28, 2026.

This Trip.com deal was found by Cheapflights users on 4/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/24:59 pm
STL
-
SJU
1 stop8h 02m
Frontier
Sat 5/93:33 pm
SJU
-
STL
1 stop9h 48m
Frontier
Deal found 4/23$233
This Priceline deal was found by Cheapflights users on 4/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/114:19 pm
STL
-
SJU
1 stop8h 49m
Frontier
Thu 5/143:03 am
SJU
-
STL
1 stop22h 18m
Frontier
Deal found 4/26$236
This Frontier deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/14:19 pm
STL
-
SJU
1 stop8h 52m
Frontier
Thu 6/46:09 pm
SJU
-
STL
1 stop6h 48m
Frontier
Deal found 4/27$243
This Priceline deal was found by Cheapflights users on 4/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/24:59 pm
STL
-
SJU
1 stop8h 02m
Frontier
Fri 5/83:33 pm
SJU
-
STL
1 stop9h 48m
Frontier
Deal found 4/24$256
This Frontier deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/14:09 pm
STL
-
SJU
1 stop9h 02m
Frontier
Thu 8/66:32 am
SJU
-
STL
1 stop9h 17m
Frontier
Deal found 4/27$258
This Priceline deal was found by Cheapflights users on 4/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/244:59 pm
STL
-
SJU
1 stop8h 02m
Frontier
Thu 4/303:21 am
SJU
-
STL
1 stop20h 58m
Frontier
Deal found 4/23$261
This Frontier deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/124:17 pm
STL
-
SJU
1 stop8h 52m
Frontier
Fri 6/194:05 pm
SJU
-
STL
1 stop9h 04m
Frontier
Deal found 4/28$276
This Frontier deal was found by Cheapflights users on 4/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/204:17 pm
STL
-
SJU
1 stop8h 52m
Frontier
Sat 6/276:00 am
SJU
-
STL
1 stop19h 09m
Frontier
Deal found 4/25$277
This Kiwi.com deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/196:33 pm
STL
-
SJU
2 stops21h 53m
Frontier
Fri 5/295:15 pm
SJU
-
STL
1 stop16h 40m
Frontier
Deal found 4/27$282

Find flight deals from St. Louis to San Juan

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to San Juan (PR1). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated April 28, 2026.

Round-trip from

$236
(Priceline)

One-way from

$88
(Priceline)

Popular in

December

Cheapest in

September

Average price

$339
From Lambert-St Louis to San Juan
One-way flight from Lambert-St Louis to San Juan
Highest demand for flights based on searches. 19% potential increase in price ($100 potential increase over avg. RT price).
Cheapest flight prices on average. 4% potential price decrease ($18 potential savings vs. average RT price).
Average for round-trip flights in April 2026

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to San Juan that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 28, 2026.
Use the filters below to find and compare flights from St. Louis to San Juan that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 9/5

5:05 am-2:00 pm

1 stop7h 55m

San Juan Luis Munoz Marin Intl

Sat 9/19

10:25 am-7:45 pm

1 stop10h 20m

$336
Quickest round-trip

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 8/1

8:00 am-4:45 pm

1 stop7h 45m

San Juan Luis Munoz Marin Intl

Thu 8/6

5:56 pm-11:53 pm

1 stop6h 57m

$336

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Tue 9/1

7:15 am-6:10 pm

2 stops9h 55m

San Juan Luis Munoz Marin Intl

Sun 9/6

5:30 am-3:50 pm

2 stops11h 20m

$427

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sun 9/20

6:00 am-4:31 pm

1 stop9h 31m

San Juan Luis Munoz Marin Intl

Sat 9/26

5:41 pm-11:37 pm

1 stop6h 56m

$436

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 7/17

2:50 pm-12:05 am

1 stop8h 15m

San Juan Luis Munoz Marin Intl

Sat 8/15

5:05 am-12:35 pm

2 stops8h 30m

$467

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 5/28

6:00 am-9:24 pm

2 stops14h 24m

San Juan Luis Munoz Marin Intl

Tue 6/2

1:00 am-12:11 pm

2 stops12h 11m

$520

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 5/28

6:00 am-9:24 pm

2 stops14h 24m

San Juan Luis Munoz Marin Intl

Wed 6/3

1:00 am-12:11 pm

2 stops12h 11m

$520

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 6/27

9:23 am-8:34 pm

1 stop10h 11m

San Juan Luis Munoz Marin Intl

Tue 6/30

1:00 am-12:11 pm

2 stops12h 11m

$557

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 5/29

2:10 pm-11:55 pm

2 stops8h 45m

San Juan Luis Munoz Marin Intl

Mon 6/1

5:35 am-3:30 pm

2 stops10h 55m

$621

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 6/19

5:41 pm-8:34 pm

1 stop25h 53m

San Juan Luis Munoz Marin Intl

Tue 6/23

1:00 am-12:11 pm

2 stops12h 11m

$622

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/23

Showing 1-10 of 21 resultsSorted by cheapest first
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3

Best time to book a flight from St. Louis to San Juan

Have a flexible travel schedule? Discover the best time to fly to San Juan from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

How far ahead should I book a flight from St. Louis to San Juan?

The price you pay for your flight from St. Louis to San Juan may vary depending on when you book. For the best chance of a lower fare, look to book 53 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from St. Louis to San Juan?

Currently, July is the cheapest month in which you can book a flight from St. Louis to San Juan (average of $101). Flying from St. Louis to San Juan in April is currently the most expensive (average of $193). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost to fly round-trip from St. Louis to San Juan?

How often are flights from St. Louis to San Juan delayed?

About 31% of weekly flights between St. Louis and San Juan have experienced delays in the past year, with the average delay time being 91 minutes.

What is the most punctual flight time for St. Louis to San Juan flights?

Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.

What day of the week experiences the fewest flight delays on this route?

Saturday tends to have the lowest number of delays on this route, whereas Monday has historically faced a higher average of delays compared to other days of the week.

Which airline has the best punctuality record on St. Louis to San Juan flights?

Over the last year, Southwest have had the lowest number of delays on this route, with just 30% of flights being delayed.

Reviews of airlines servicing San Juan

Get insights into the airlines that provide service to San Juan. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to San Juan. Reviews last updated April 28, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andUnited Airlines from St. Louis to San Juan to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to San Juan. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
  • What airport do you fly from for flights from St. Louis to San Juan?

    Most people fly from Lambert-St Louis (STL) if they book a flight from St. Louis to San Juan. On average, Lambert-St Louis has 0 outbound flights to San Juan per day from 6 airlines. Lambert-St Louis is conveniently located just 12.7 mi from St. Louis’s city center.

  • How long is the flight from St. Louis to San Juan?

    For as low as $336, Southwest can have you in San Juan from St. Louis in 7h 45m. The distance between St. Louis and San Juan is about 2024 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from St. Louis to San Juan round-trip?

    Our cheapest airline available from St. Louis to San Juan is Frontier. Our recent data shows that you can find tickets from as low as $138 on this airline. Additional options worth looking into are Spirit Airlines and Delta, starting at $170 and $197 round-trip. Frontier is 67% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from St. Louis to San Juan one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $98. Southwest flights start at $112 while deals on United Airlines start at $112 one-way.

  • Can I find deals for flights from St. Louis to San Juan that include hotel bookings?

    Yes. In addition to deals on St. Louis to San Juan flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to San Juan?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to San Juan.

  • Can I find deals for business class flights from St. Louis to San Juan?

    Yes. Cheapflights offers flight deals from St. Louis to San Juan by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to San Juan?

    Currently, July is the cheapest month in which you can book a flight from St. Louis to San Juan (average of $101). Flying from St. Louis to San Juan in April is currently the most expensive (average of $193). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Alternative routes for St. Louis to San Juan

See prices for flight routes from nearby airports that may be better suited for you.

Top 6 airlines flying from St. Louis to San Juan

Discover the top 6 airlines that operate flights from St. Louis to San Juan. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 28, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$138Average$330FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$170Average$334FlexibilityNo cancel feeOn-time65%
DeltaCheapest$197Average$383FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$219Average$512FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$225Average$360FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$226Average$522FlexibilityNo cancel feeOn-time71%

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