San Juan

$160+ 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 8/12. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SJU
Jul 12 — Jul 191
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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 June 12, 2026.

This Delta deal was found by Cheapflights users on 6/8. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/2112:52 pm
STL
-
SJU
1 stop8h 37m
Delta
Tue 8/257:00 am
SJU
-
STL
1 stop8h 33m
Delta
Deal found 6/8$336
This American Airlines deal was found by Cheapflights users on 6/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/23:25 pm
STL
-
SJU
1 stop7h 34m
American Airlines
Wed 9/96:27 am
SJU
-
STL
2 stops12h 03m
American Airlines
Deal found 6/10$341
This United Airlines deal was found by Cheapflights users on 6/9. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/66:00 am
STL
-
SJU
1 stop7h 44m
United Airlines
Sat 9/121:00 am
SJU
-
STL
2 stops10h 12m
United Airlines
Deal found 6/9$346
This Southwest deal was found by Cheapflights users on 6/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/292:05 pm
STL
-
SJU
2 stops9h 30m
Southwest
Tue 11/36:45 am
SJU
-
STL
2 stops14h 35m
Southwest
Deal found 6/10$356
This United Airlines deal was found by Cheapflights users on 6/11. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/68:00 am
STL
-
SJU
2 stops11h 38m
United Airlines
Fri 9/111:00 am
SJU
-
STL
2 stops12h 03m
United Airlines
Deal found 6/11$359
This American Airlines deal was found by Cheapflights users on 6/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/306:00 am
STL
-
SJU
2 stops9h 57m
American Airlines
Thu 9/31:38 pm
SJU
-
STL
2 stops10h 02m
American Airlines
Deal found 6/10$361
This Southwest deal was found by Cheapflights users on 6/9. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/34:55 pm
STL
-
SJU
1 stop5h 55m
Southwest
Mon 9/78:55 pm
SJU
-
STL
1 stop11h 45m
Southwest
Deal found 6/9$376
This Southwest deal was found by Cheapflights users on 6/7. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/255:00 am
STL
-
SJU
1 stop7h 45m
Southwest
Thu 10/296:30 am
SJU
-
STL
2 stops9h 40m
Southwest
Deal found 6/7$381
This Kiwi.com deal was found by Cheapflights users on 6/10. 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.
Sun 8/26:34 pm
STL
-
SJU
2 stops42h 26m
Frontier
Sun 8/95:15 pm
SJU
-
STL
1 stop16h 42m
Frontier
Deal found 6/10$382
This Kiwi.com deal was found by Cheapflights users on 6/11. 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 7/286:34 pm
STL
-
SJU
1 stop18h 42m
Frontier
Mon 8/106:26 am
SJU
-
STL
2 stops36h 11m
Frontier
Deal found 6/11$384
This Kiwi.com deal was found by Cheapflights users on 6/9. 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.
Mon 8/34:57 pm
STL
-
SJU
2 stops43h 44m
Frontier
Sun 8/95:15 pm
SJU
-
STL
1 stop16h 42m
Frontier
Deal found 6/9$388

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 June 12, 2026.

Round-trip from

$336
(Delta)

One-way from

$160
(Kiwi.com)

Popular in

December

Cheapest in

September

Average price

$475
From Lambert-St Louis to San Juan
One-way flight from Lambert-St Louis to San Juan
Highest demand for flights based on searches. 15% potential increase in price ($76 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 June 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 June 12, 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

Sun 8/16

3:30 pm-12:30 am

1 stop8h 00m

San Juan Luis Munoz Marin Intl

Sat 8/22

10:25 am-7:45 pm

1 stop10h 20m

$336

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 9/24

10:00 am-10:00 pm

1 stop11h 00m

San Juan Luis Munoz Marin Intl

Wed 9/30

7:30 am-5:40 pm

1 stop11h 10m

$336

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 10/22

6:30 am-6:10 pm

1 stop10h 40m

San Juan Luis Munoz Marin Intl

Mon 10/26

1:05 pm-8:30 pm

1 stop8h 25m

$336
Quickest round-trip

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Wed 9/2

6:00 am-4:38 pm

1 stop9h 38m

San Juan Luis Munoz Marin Intl

Wed 9/9

7:30 am-2:38 pm

1 stop8h 08m

$336

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 8/21

9:15 am-8:05 pm

1 stop9h 50m

San Juan Luis Munoz Marin Intl

Tue 8/25

11:50 am-7:55 pm

1 stop9h 05m

$336

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 10/2

1:50 pm-8:55 pm

1 stop6h 05m

San Juan Luis Munoz Marin Intl

Tue 10/6

6:10 am-7:35 pm

2 stops14h 25m

$336

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sun 10/25

6:45 am-4:30 pm

2 stops8h 45m

San Juan Luis Munoz Marin Intl

Thu 10/29

6:30 am-3:10 pm

2 stops9h 40m

$381

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 10/22

10:15 am-8:55 pm

2 stops9h 40m

San Juan Luis Munoz Marin Intl

Sat 10/31

5:30 am-2:50 pm

1 stop10h 20m

$381

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 11/6

8:20 pm-10:00 am

1 stop11h 40m

San Juan Luis Munoz Marin Intl

Wed 11/11

5:45 am-1:40 pm

2 stops9h 55m

$396
Cheapest one-way

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Tue 8/4

6:34 pm-1:41 pm

2 stops42h 07m

$166

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/12

Showing 1-10 of 21 resultsSorted by cheapest first
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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

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 $104). Flying from St. Louis to San Juan in August is currently the most expensive (average of $219). 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.

What is the cheapest time of day to fly from STL to SJU?

Find hourly flight availability from St. Louis to San Juan. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 12, 2026.

When flying from St. Louis to San Juan, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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 33% of weekly flights between St. Louis and San Juan have experienced delays in the past year, with the average delay time being 92 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 32% of flights being delayed.

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.

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 June 12, 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

Boarding

8.1

Crew

8.6

Food

7.0

Overall

7.9

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

7.9

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

7.9

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

7.9

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

7.9

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

Comfort

8.0

Boarding

8.1

Crew

8.6

Food

7.0

Overall

7.9

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

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 5 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 8h. 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 Delta and Southwest, starting at $205 and $220 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 $104). Flying from St. Louis to San Juan in August is currently the most expensive (average of $219). 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 5 airlines flying from St. Louis to San Juan

Discover the top 5 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 June 12, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$138Average$325FlexibilityNo cancel feeOn-time62%
DeltaCheapest$205Average$373FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$220Average$486FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$225Average$403FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$250Average$500FlexibilityNo cancel feeOn-time71%

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