$90+ 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 1/26. Fares are subject to change and may not be available on all flights or dates of travel.
Find cheap flights from St. Louis to San Juan with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from Lambert-St Louis to San Juan are usually found in September or April, booked 75 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday
Cheap flight deals from St. Louis to San Juan
Cheapest flights from St. Louis to San JuanExplore 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 December 4, 2025.
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 December 4, 2025.
This Frontier deal was found by Cheapflights users on 12/2. 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.
This CheapOair deal was found by Cheapflights users on 12/4. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Priceline deal was found by Cheapflights users on 12/4. 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.
This Frontier deal was found by Cheapflights users on 12/3. 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.
This Frontier deal was found by Cheapflights users on 12/3. 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.
This Priceline deal was found by Cheapflights users on 12/4. 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.
This Frontier deal was found by Cheapflights users on 12/3. 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.
This Priceline deal was found by Cheapflights users on 12/3. 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.
This CheapOair deal was found by Cheapflights users on 12/4. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Priceline deal was found by Cheapflights users on 12/4. 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.
This FlightHub deal was found by Cheapflights users on 12/4. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
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 December 4, 2025.
Round-trip from | $180 (Priceline) |
|---|---|
One-way from | $90 (Priceline) |
Popular in | December |
Cheapest in | September |
Average price | $615 |
Cheapflights Fare Finder
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
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Thu 2/19
5:11 pm-9:55 am
1 stop14h 44m
San Juan Luis Munoz Marin Intl
Sun 2/22
3:55 am-10:33 pm
1 stop20h 38m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Sun 1/18
10:06 am-11:29 pm
1 stop11h 23m
San Juan Luis Munoz Marin Intl
Sat 1/24
4:36 pm-11:33 pm
1 stop8h 57m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Sun 2/22
6:00 am-4:36 pm
1 stop8h 36m
San Juan Luis Munoz Marin Intl
Thu 2/26
2:05 am-12:25 pm
2 stops12h 20m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Fri 2/27
5:11 pm-2:50 am
1 stop7h 39m
San Juan Luis Munoz Marin Intl
Mon 3/2
11:05 am-10:33 pm
1 stop13h 28m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Wed 3/4
2:35 pm-11:10 pm
1 stop6h 35m
San Juan Luis Munoz Marin Intl
Sat 3/7
6:30 am-12:40 pm
1 stop8h 10m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Mon 1/26
11:20 am-12:36 am
2 stops11h 16m
San Juan Luis Munoz Marin Intl
Wed 1/28
2:05 am-10:41 am
1 stop10h 36m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Thu 2/26
2:05 pm-11:25 pm
1 stop7h 20m
San Juan Luis Munoz Marin Intl
Tue 3/10
5:15 am-3:30 pm
1 stop11h 15m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Tue 3/3
8:15 am-5:05 pm
1 stop6h 50m
San Juan Luis Munoz Marin Intl
Sun 3/8
9:50 pm-7:55 am
1 stop11h 05m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Mon 2/23
9:55 am-10:22 pm
2 stops10h 27m
San Juan Luis Munoz Marin Intl
Thu 2/26
2:05 am-12:25 pm
2 stops12h 20m
St. LouisSan Juan
STL - SJU
STLSJU
Lambert-St Louis
Mon 1/26
10:16 am-6:40 pm
1 stop6h 24m
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.
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?
Use this chart to determine the optimal time to book a round-trip flight from St. Louis to San Juan. Price data was last updated on November 28, 2025.
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 75 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, May is the cheapest month in which you can book a flight from St. Louis to San Juan (average of $140). Flying from St. Louis to San Juan in December is currently the most expensive (average of $260). 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 December 4, 2025.
When flying from St. Louis to San Juan, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 58% versus a flight in the morning.
What is the cheapest day to fly from St. Louis to San Juan?
Use this chart to determine the cheapest time to fly round-trip from St. Louis to San Juan. Price data was last updated on December 16, 2024.
Travelers seeking maximum savings on their St. Louis to San Juan flight should consider departing on Tuesday evenings when fares are most often at their lowest. Saturday mornings flights should be avoided if possible as fares are typically the most expensive at this time.
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 17% of weekly flights between St. Louis and San Juan have experienced delays in the past year, with the average delay time being 85 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 15% 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 December 4, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta, and United 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.
Crew
Overall
Comfort
Food
Entertainment
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Crew
Overall
Comfort
Food
Entertainment
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Crew
Overall
Comfort
Food
Entertainment
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Crew
Overall
Comfort
Food
Entertainment
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Crew
Overall
Comfort
Food
Entertainment
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Crew
Overall
Comfort
Food
Entertainment
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
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.
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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 December 4, 2025.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$140 | Average$289 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$170 | Average$334 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$208 | Average$384 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$219 | Average$596 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$225 | Average$393 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$246 | Average$527 | FlexibilityNo cancel fee | On-time71% |