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.
1 adult
0 bags

Discover deals from 900+ travel sites with momondo.

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 - 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
4:09 pm - 2:11 am
STL
-
SJU
9h 02m
1 stop
Frontier Logo
6:31 pm - 11:59 pm
SJU
-
STL
6h 28m
1 stop
$256Frontier
Mon, Jul 20 - Wed, Jul 29
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 - Mon, Jul 27
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
$281Frontier
Wed, Jul 29 - Thu, Jul 30
Frontier Logo
4:09 pm - 5:36 pm
STL
-
SJU
24h 27m
1 stop
Frontier Logo
6:00 am - 11:59 pm
SJU
-
STL
18h 59m
1 stop
$283Frontier
Tue, Jul 21 - Fri, Jul 31
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
9:24 am - 11:59 pm
SJU
-
STL
15h 35m
1 stop
$303Frontier
Sat, Jul 25 - Sat, Aug 1
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
4:52 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

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Frontier flights from St. Louis to San Juan

Our best Frontier deals on St. Louis to San Juan flight tickets
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
Jul 20
STL4:09 pmLambert-St Louis
9h 02m
1 stop
SJU2:11 amSan Juan Luis Munoz Marin Intl
Jul 29
SJU6:31 pmSan Juan Luis Munoz Marin Intl
6h 28m
1 stop
STL11:59 pmLambert-St Louis
$256
Frontier
Jul 25
STL3:34 pmLambert-St Louis
12h 28m
1 stop
SJU5:02 amSan Juan Luis Munoz Marin Intl
Jul 31
SJU4:05 pmSan Juan Luis Munoz Marin Intl
8h 54m
1 stop
STL11:59 pmLambert-St Louis
$258

American Airlines flights from St. Louis to San Juan

Our best American Airlines deals on St. Louis to San Juan flight tickets
American Airlines
May 25
STL7:30 amLambert-St Louis
14h 15m
1 stop
SJU10:45 pmSan Juan Luis Munoz Marin Intl
May 29
SJU6:20 amSan Juan Luis Munoz Marin Intl
11h 39m
1 stop
STL4:59 pmLambert-St Louis
$336
American Airlines
May 18
STL6:29 amLambert-St Louis
10h 41m
2 stops
SJU6:10 pmSan Juan Luis Munoz Marin Intl
May 28
SJU5:30 amSan Juan Luis Munoz Marin Intl
17h 12m
1 stop
STL9:42 pmLambert-St Louis
$446
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

momondo 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, momondo users made 832,500 searches. Data last updated May 6, 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 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
Quickest round-trip

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Mon 7/20

4:09 pm-2:11 am

1 stop9h 02m

San Juan Luis Munoz Marin Intl

Wed 7/29

6:31 pm-11:59 pm

1 stop6h 28m

$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

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

Mon 7/27

6:31 pm-11:59 pm

1 stop6h 28m

$276

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Wed 7/29

4:09 pm-7:57 am

1 stop14h 48m

San Juan Luis Munoz Marin Intl

Thu 7/30

6:31 pm-11:59 pm

1 stop6h 28m

$281

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Tue 7/21

4:09 pm-5:36 pm

1 stop24h 27m

San Juan Luis Munoz Marin Intl

Fri 7/31

6:00 am-11:59 pm

1 stop18h 59m

$283

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

Sat 8/1

9:24 am-11:59 pm

1 stop15h 35m

$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

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

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?

What is the cheapest month to fly to San Juan?

If you’re not able to fly to San Juan in July, then November is your next best option. Flight prices from St. Louis to San Juan during November average around $113.

What is the cheapest Lambert-St Louis to San Juan flight route?

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

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

You are more likely to see cheaper flights to San Juan from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to San Juan 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 from St. Louis for as low as $348 on momondo.

Cheap St. Louis to San Juan flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to San Juan

Fastest flight time

6h 38m

Direct flights

Sun

Airports in San Juan

2 airports
The fastest flight from St. Louis to San Juan takes 6h 38m
Direct flights go from St. Louis to San Juan on Sunday. There are no airlines offering direct flights.
There are 2 airports in San Juan. From St. Louis there are direct flights to San Juan Luis Munoz Marin Intl (SJU).

Frequently asked questions about flying from St. Louis to San Juan

  • How far is Lambert-St Louis to San Juan by plane?

    There are 2005.8 mi between Lambert-St Louis and San Juan. In terms of flight time, this usually takes a little over 6h 38m.

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

    Prices for flights from Lambert-St Louis Airport to San Juan are refreshed on a daily basis.

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

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

    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.

  • What documentation or ID do you need to fly to San Juan?

    The travel and health documents you'll need for your trip to San Juan 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. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Best airlines flying from St. Louis to San Juan

Compare and see reviews for airlines that fly from St. Louis to San Juan with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $138Free CancellationRating
5.6
2,964 reviews
Search Frontier flights
DeltaPriceFrom $197Free CancellationRating
7.9
8,459 reviews
Search Delta flights
SouthwestPriceFrom $220Free CancellationRating
7.9
4,305 reviews
Search Southwest flights
United AirlinesPriceFrom $225Free CancellationRating
7.4
9,684 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

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?

Yes. momondo allows you to filter the results for St. Louis to San Juan flights to just show those with flexible booking policies.

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to San Juan.

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 can track prices for St. Louis to San Juan flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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1 adult
Fri 6/5
Fri 6/12

Find better results for your trip to Puerto Rico

Fly into one of these airports located in San Juan

Airports listed have a maximum distance of 7.1 mi from San Juan