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Cheap flights from St. Louis to San Juan from $120

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to San Juan departing on 7/25. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from St. Louis to San Juan

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
4:09 pm - 7:57 am
STL
-
SJU
14h 48m
1 stop
Frontier Logo
6:31 pm - 11:59 pm
SJU
-
STL
6h 28m
1 stop
$236Frontier
Wed, Aug 5 - Wed, Aug 12
Frontier Logo
4:09 pm - 2:11 am
STL
-
SJU
9h 02m
1 stop
Frontier Logo
6:00 am - 11:59 pm
SJU
-
STL
18h 59m
1 stop
$240Frontier
Sat, Aug 1 - Mon, Aug 10
Frontier Logo
4:10 pm - 1:54 am
STL
-
SJU
8h 44m
1 stop
Frontier Logo
4:05 pm - 12:14 am
SJU
-
STL
9h 09m
1 stop
$256Frontier
Wed, Aug 19 - Sun, Aug 23
Frontier Logo
3:34 pm - 5:02 am
STL
-
SJU
12h 28m
1 stop
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
$258Frontier
Sat, Jul 25 - Fri, Jul 31
Frontier Logo
4:09 pm - 2:11 am
STL
-
SJU
9h 02m
1 stop
Frontier Logo
6:31 pm - 11:59 pm
SJU
-
STL
6h 28m
1 stop
$276Frontier
Thu, Jul 23 - Thu, Jul 30
Frontier Logo
4:09 pm - 5:36 pm
STL
-
SJU
24h 27m
1 stop
Frontier Logo
3:06 am - 11:59 pm
SJU
-
STL
21h 53m
1 stop
$301Frontier
Tue, Aug 4 - Mon, Aug 10
Frontier Logo
3:34 pm - 5:02 am
STL
-
SJU
12h 28m
1 stop
Frontier Logo
4:05 pm - 11:59 pm
SJU
-
STL
8h 54m
1 stop
$303Frontier
Sat, Jul 25 - Fri, Jul 31
Frontier Logo
6:33 pm - 11:59 pm
STL
-
SJU
28h 26m
2 stops
Frontier Logo
5:15 pm - 8:55 am
SJU
-
STL
16h 40m
1 stop
$304Frontier
Thu, May 28 - Fri, Jun 5
Frontier Logo
4:10 pm - 1:16 pm
STL
-
SJU
20h 06m
1 stop
Frontier Logo
6:41 pm - 5:30 pm
SJU
-
STL
23h 49m
2 stops
$316Frontier
Wed, Aug 19 - Wed, Aug 26
Frontier Logo
4:52 pm - 2:16 pm
STL
-
SJU
20h 24m
1 stop
Frontier Logo
7:30 am - 5:37 pm
SJU
-
STL
35h 07m
2 stops
$317Frontier
Sat, Jul 25 - Mon, Aug 3

Frontier flights from St. Louis to San Juan Luis Munoz Marin Intl Airport

Our best Frontier deals on St. Louis to San Juan Luis Munoz Marin Intl Airport flight tickets
Frontier
Aug 5
STL4:09 pmLambert-St Louis
14h 48m
1 stop
SJU7:57 amSan Juan Luis Munoz Marin Intl
Aug 12
SJU6:31 pmSan Juan Luis Munoz Marin Intl
6h 28m
1 stop
STL11:59 pmLambert-St Louis
$236
Frontier
Aug 1
STL4:09 pmLambert-St Louis
9h 02m
1 stop
SJU2:11 amSan Juan Luis Munoz Marin Intl
Aug 10
SJU6:00 amSan Juan Luis Munoz Marin Intl
18h 59m
1 stop
STL11:59 pmLambert-St Louis
$240
Frontier
Aug 19
STL4:10 pmLambert-St Louis
8h 44m
1 stop
SJU1:54 amSan Juan Luis Munoz Marin Intl
Aug 23
SJU4:05 pmSan Juan Luis Munoz Marin Intl
9h 09m
1 stop
STL12:14 amLambert-St Louis
$256

American Airlines flights from St. Louis to San Juan Luis Munoz Marin Intl Airport

Our best American Airlines deals on St. Louis to San Juan Luis Munoz Marin Intl Airport flight tickets
American Airlines
Aug 19
STL6:00 amLambert-St Louis
11h 24m
2 stops
SJU6:24 pmSan Juan Luis Munoz Marin Intl
Aug 26
SJU3:44 pmSan Juan Luis Munoz Marin Intl
8h 58m
1 stop
STL11:42 pmLambert-St Louis
$341
American Airlines
May 19
STL9:34 amLambert-St Louis
12h 29m
1 stop
SJU11:03 pmSan Juan Luis Munoz Marin Intl
May 26
SJU6:20 amSan Juan Luis Munoz Marin Intl
11h 39m
1 stop
STL4:59 pmLambert-St Louis
$523
American Airlines
May 20
STL6:29 amLambert-St Louis
14h 36m
1 stop
SJU10:05 pmSan Juan Luis Munoz Marin Intl
May 23
SJU6:20 amSan Juan Luis Munoz Marin Intl
16h 00m
1 stop
STL9:20 pmLambert-St Louis
$528

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to San Juan Luis Munoz Marin Intl Airport 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, momondo users made 832,500 searches. Data last updated May 7, 2026.
Use the filters below to find and compare flights from St. Louis to San Juan Luis Munoz Marin Intl Airport 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

Wed 8/5

4:09 pm-7:57 am

1 stop14h 48m

San Juan Luis Munoz Marin Intl

Wed 8/12

6:31 pm-11:59 pm

1 stop6h 28m

$236

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 8/1

4:09 pm-2:11 am

1 stop9h 02m

San Juan Luis Munoz Marin Intl

Mon 8/10

6:00 am-11:59 pm

1 stop18h 59m

$240

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Wed 8/19

4:10 pm-1:54 am

1 stop8h 44m

San Juan Luis Munoz Marin Intl

Sun 8/23

4:05 pm-12:14 am

1 stop9h 09m

$256

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 7/25

3:34 pm-5:02 am

1 stop12h 28m

San Juan Luis Munoz Marin Intl

Fri 7/31

4:05 pm-11:59 pm

1 stop8h 54m

$258
Quickest round-trip

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 7/23

4:09 pm-2:11 am

1 stop9h 02m

San Juan Luis Munoz Marin Intl

Thu 7/30

6:31 pm-11:59 pm

1 stop6h 28m

$276

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Tue 8/4

4:09 pm-5:36 pm

1 stop24h 27m

San Juan Luis Munoz Marin Intl

Mon 8/10

3:06 am-11:59 pm

1 stop21h 53m

$301

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 7/25

3:34 pm-5:02 am

1 stop12h 28m

San Juan Luis Munoz Marin Intl

Fri 7/31

4:05 pm-11:59 pm

1 stop8h 54m

$303

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 5/28

6:33 pm-11:59 pm

2 stops28h 26m

San Juan Luis Munoz Marin Intl

Fri 6/5

5:15 pm-8:55 am

1 stop16h 40m

$304

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Wed 8/19

4:10 pm-1:16 pm

1 stop20h 06m

San Juan Luis Munoz Marin Intl

Wed 8/26

6:41 pm-5:30 pm

2 stops23h 49m

$316

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 7/25

4:52 pm-2:16 pm

1 stop20h 24m

San Juan Luis Munoz Marin Intl

Mon 8/3

7:30 am-5:37 pm

2 stops35h 07m

$317

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to San Juan from

How to get the cheapest flight ticket from St. Louis to San Juan Luis Munoz Marin Intl Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between St. Louis and San Juan Luis Munoz Marin Intl Airport?

What is the cheapest month to fly to San Juan Luis Munoz Marin Intl Airport?

If you aren’t able to travel to San Juan Luis Munoz Marin Intl Airport during the month of September, then flying in October is also cheap. Prices for this month can be found on momondo for an average of $331.

What is the cheapest Lambert-St Louis to San Juan Luis Munoz Marin Intl flight route?

Fly from Lambert-St Louis to San Juan Luis Munoz Marin Intl for the best Lambert-St Louis - San Juan Luis Munoz Marin Intl flight prices

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

You are more likely to see cheaper flights to San Juan Luis Munoz Marin Intl Airport from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to San Juan Luis Munoz Marin Intl Airport for around $424 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to San Juan Luis Munoz Marin Intl Airport from St. Louis for as low as $348 on momondo.

How have St. Louis to San Juan Luis Munoz Marin Intl Airport flight prices changed over time?

As of May 2026, prices for St. Louis to San Juan Luis Munoz Marin Intl Airport flights are approximately 120% more expensive when compared to flights at the same time last year.

When to book flights from St. Louis to San Juan Luis Munoz Marin Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to San Juan Luis Munoz Marin Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to San Juan Luis Munoz Marin Intl Airport (STL to SJU) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to San Juan Luis Munoz Marin Intl Airport

Fastest flight time

6h 03m

Direct flights

Sun
The fastest flight from St. Louis to San Juan Luis Munoz Marin Intl Airport takes 6h 03m
Direct flights go from St. Louis to San Juan Luis Munoz Marin Intl Airport on Sunday. There are no airlines offering direct flights.
Search flight deals

Frequently asked questions about flying from St. Louis to San Juan Luis Munoz Marin Intl Airport

  • How far is Lambert-St Louis to San Juan Luis Munoz Marin Intl by plane?

    There are 2011.8 mi between Lambert-St Louis and San Juan Luis Munoz Marin Intl. A reasonable flight in good conditions will take 6h 03m.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to San Juan Luis Munoz Marin Intl Airport?

    Prices for flights from Lambert-St Louis Airport to San Juan Luis Munoz Marin Intl Airport are updated daily.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to San Juan Luis Munoz Marin Intl Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to San Juan Luis Munoz Marin Intl Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to San Juan Luis Munoz Marin Intl Airport.

  • What documentation or ID do you need to fly to San Juan Luis Munoz Marin Intl Airport?

    The travel and health documents you'll need for your trip to San Juan Luis Munoz Marin Intl Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at San Juan Luis Munoz Marin Intl Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from St. Louis to San Juan Luis Munoz Marin Intl Airport?

  • What is the most popular airline from St. Louis to San Juan Luis Munoz Marin Intl Airport?

Best airlines flying from St. Louis to San Juan Luis Munoz Marin Intl Airport

Compare and see reviews for airlines that fly from St. Louis to San Juan Luis Munoz Marin Intl Airport with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $138Free CancellationRating
5.6
2,963 reviews
Search Frontier flights
DeltaPriceFrom $197Free CancellationRating
7.9
8,456 reviews
Search Delta flights
SouthwestPriceFrom $220Free CancellationRating
7.9
4,302 reviews
Search Southwest flights
United AirlinesPriceFrom $225Free CancellationRating
7.4
9,694 reviews
Search United Airlines flights
American AirlinesPriceFrom $226Free CancellationRating
7.1
11,667 reviews
Search American Airlines flights
Spirit AirlinesPriceFrom $233Free CancellationRating
6.3
8,638 reviews
Search Spirit Airlines flights

Traveling to a place near San Juan?

Book flights to San Juan if you plan to visit one of these locations
Carolina
Fajardo
Dorado
Luquillo
Caguas
Humacao
Rio Grande
Bayamón

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to San Juan?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from St. Louis to San Juan. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from St. Louis to San Juan with flexible booking policies on momondo?

All flight searches from St. Louis to San Juan on momondo can be filtered to show those which offer flexible booking policies.

How can momondo help me find flights from St. Louis to San Juan?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to San Juan from St. Louis.

I’m not ready to book a flight from St. Louis to San Juan right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to San Juan from St. Louis. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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