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Cheap flights from St. Louis to San Juan from $103

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 9/22. 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

Delta Logo
6:00 am - 2:11 pmSTL-SJU
7h 11m1 stop
Delta Logo
7:15 am - 2:43 pmSJU-STL
8h 28m1 stop
$205Delta
Find Deal
Sat, Oct 25 - Sat, Nov 1
United Airlines Logo
6:15 am - 3:42 pmSTL-SJU
8h 27m1 stop
United Airlines Logo
1:05 am - 2:25 pmSJU-STL
14h 20m2 stops
$220United Airlines
Find Deal
Tue, Oct 14 - Mon, Oct 27
Frontier Logo
5:11 pm - 2:50 amSTL-SJU
7h 39m1 stop
Frontier Logo
3:55 am - 8:45 amSJU-STL
6h 50m1 stop
$269Frontier
Find Deal
Fri, Dec 5 - Thu, Dec 11
Spirit Airlines Logo
10:35 am - 11:04 amSTL-SJU
23h 29m1 stop
Spirit Airlines Logo
3:19 pm - 9:40 amSJU-STL
19h 21m2 stops
$271Spirit Airlines
Find Deal
Sun, Sep 21 - Sat, Sep 27
Spirit Airlines Logo
2:30 pm - 12:56 amSTL-SJU
9h 26m2 stops
Spirit Airlines Logo
2:11 am - 1:32 pmSJU-STL
12h 21m2 stops
$277Spirit Airlines
Find Deal
Thu, Aug 28 - Sat, Aug 30
American Airlines Logo
5:18 am - 2:15 pmSTL-SJU
7h 57m1 stop
American Airlines Logo
3:00 pm - 11:54 pmSJU-STL
9h 54m1 stop
$278American Airlines
Find Deal
Sat, Oct 4 - Tue, Oct 7
American Airlines Logo
6:00 am - 11:59 pmSTL-SJU
16h 59m1 stop
American Airlines Logo
7:10 am - 11:58 pmSJU-STL
17h 48m1 stop
$284American Airlines
Find Deal
Fri, Oct 17 - Sun, Oct 19
Frontier Logo
1:57 pm - 11:59 pmSTL-SJU
9h 02m1 stop
Frontier Logo
3:39 am - 1:07 pmSJU-STL
10h 28m1 stop
$286Frontier
Find Deal
Mon, Sep 15 - Sat, Sep 20
Southwest Logo
7:50 am - 9:45 pmSTL-SJU
11h 55m1 stop
Southwest Logo
5:40 am - 10:20 amSJU-STL
6h 40m1 stop
$296Southwest
Find Deal
Thu, Nov 13 - Sun, Nov 16
Southwest Logo
6:05 am - 6:40 pmSTL-SJU
10h 35m1 stop
Southwest Logo
4:10 pm - 7:30 pmSJU-STL
5h 20mnonstop
$336Southwest
Find Deal
Sat, Nov 15 - Sat, Nov 22

United Airlines flights from St. Louis to San Juan

Our best United Airlines deals on St. Louis to San Juan flight tickets
United Airlines
Oct 14
STL6:15 amLambert-St Louis
8h 27m
1 stop
SJU3:42 pmSan Juan Luis Munoz Marin Intl
Oct 27
SJU1:05 amSan Juan Luis Munoz Marin Intl
14h 20m
2 stops
STL2:25 pmLambert-St Louis
$220
Find similar
United Airlines
Oct 14
STL6:15 amLambert-St Louis
8h 27m
1 stop
SJU3:42 pmSan Juan Luis Munoz Marin Intl
Oct 28
SJU7:30 amSan Juan Luis Munoz Marin Intl
11h 09m
2 stops
STL5:39 pmLambert-St Louis
$242
Find similar
United Airlines
Sep 23
STL6:35 amLambert-St Louis
13h 03m
2 stops
SJU8:38 pmSan Juan Luis Munoz Marin Intl
Sep 29
SJU1:05 amSan Juan Luis Munoz Marin Intl
10h 44m
2 stops
STL10:49 amLambert-St Louis
$295
Find similar

American Airlines flights from St. Louis to San Juan

Our best American Airlines deals on St. Louis to San Juan flight tickets
American Airlines
Oct 4
STL5:18 amLambert-St Louis
7h 57m
1 stop
SJU2:15 pmSan Juan Luis Munoz Marin Intl
Oct 7
SJU3:00 pmSan Juan Luis Munoz Marin Intl
9h 54m
1 stop
STL11:54 pmLambert-St Louis
$278
Find similar
American Airlines
Oct 17
STL6:00 amLambert-St Louis
16h 59m
1 stop
SJU11:59 pmSan Juan Luis Munoz Marin Intl
Oct 19
SJU7:10 amSan Juan Luis Munoz Marin Intl
17h 48m
1 stop
STL11:58 pmLambert-St Louis
$284
Find similar
American Airlines
Oct 11
STL6:00 amLambert-St Louis
16h 05m
1 stop
SJU11:05 pmSan Juan Luis Munoz Marin Intl
Oct 19
SJU7:10 amSan Juan Luis Munoz Marin Intl
17h 48m
1 stop
STL11:58 pmLambert-St Louis
$303
Find similar

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 August 14, 2025.
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

Sat 10/25

6:00 am-2:11 pm

1 stop7h 11m

San Juan Luis Munoz Marin Intl

Sat 11/1

7:15 am-2:43 pm

1 stop8h 28m

$205

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Tue 10/14

6:15 am-3:42 pm

1 stop8h 27m

San Juan Luis Munoz Marin Intl

Mon 10/27

1:05 am-2:25 pm

2 stops14h 20m

$220

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 12/5

5:11 pm-2:50 am

1 stop7h 39m

San Juan Luis Munoz Marin Intl

Thu 12/11

3:55 am-8:45 am

1 stop6h 50m

$269

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sun 9/21

10:35 am-11:04 am

1 stop23h 29m

San Juan Luis Munoz Marin Intl

Sat 9/27

3:19 pm-9:40 am

2 stops19h 21m

$271

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 8/28

2:30 pm-12:56 am

2 stops9h 26m

San Juan Luis Munoz Marin Intl

Sat 8/30

2:11 am-1:32 pm

2 stops12h 21m

$277

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 10/4

5:18 am-2:15 pm

1 stop7h 57m

San Juan Luis Munoz Marin Intl

Tue 10/7

3:00 pm-11:54 pm

1 stop9h 54m

$278

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Fri 10/17

6:00 am-11:59 pm

1 stop16h 59m

San Juan Luis Munoz Marin Intl

Sun 10/19

7:10 am-11:58 pm

1 stop17h 48m

$284

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Mon 9/15

1:57 pm-11:59 pm

1 stop9h 02m

San Juan Luis Munoz Marin Intl

Sat 9/20

3:39 am-1:07 pm

1 stop10h 28m

$286

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Thu 11/13

7:50 am-9:45 pm

1 stop11h 55m

San Juan Luis Munoz Marin Intl

Sun 11/16

5:40 am-10:20 am

1 stop6h 40m

$296

St. LouisSan Juan

STL - SJU

STLSJU

Lambert-St Louis

Sat 11/15

6:05 am-6:40 pm

1 stop10h 35m

San Juan Luis Munoz Marin Intl

Sat 11/22

4:10 pm-7:30 pm

Nonstop5h 20m

$336

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 cheapest month to fly to San Juan?

If you’re not able to fly to San Juan in September, then April is your next best option. Flight prices from St. Louis to San Juan during April average around $368.

What is the cheapest day to depart on your flight to San Juan?

The cheapest day to depart from St. Louis to San Juan is on a Wednesday when prices can be found for as low as $404. The most expensive day to fly to San Juan is Saturday, with ticket prices averaging around $636.

What is the cheapest time of day to depart on your flight to San Juan?

The cheapest time of day to fly to San Juan is in the evening when flights can be purchased for as low as $310. If you have a flexible travel schedule, then try to avoid flying at noon when prices are $660 on average. Flights to San Juan from St. Louis at noon are generally more expensive because this time of day is more convenient for travelers’ schedules.

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 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 $451 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 $335 on momondo.

What cabin class options are available on Lambert-St Louis to San Juan flights?

There are 1 cabin classes available to choose from on Lambert-St Louis to San Juan flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

Best Price Found

$103

Fastest flight time

6h 15m

Direct flights

Sun

Airports in San Juan

1 airport
The best one-way flight to San Juan from St. Louis in the past 72 hours is $103. The best round-trip flight deal from St. Louis to San Juan found on momondo in the last 72 hours is $205.
The fastest flight from St. Louis to San Juan takes 6h 15m
Direct flights go from St. Louis to San Juan on Sunday. The only airline offering direct flights is Southwest.
There is 1 airport near San Juan: San Juan Luis Munoz Marin Intl (SJU)
Search flight deals

  • 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 15m.

  • 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 $140Free CancellationRating
5.8
3,219 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $170Free CancellationRating
6.3
8,045 reviews
Search Spirit Airlines flights
DeltaPriceFrom $209Free CancellationRating
8.0
7,980 reviews
Search Delta flights
United AirlinesPriceFrom $219Free CancellationRating
7.4
8,916 reviews
Search United Airlines flights
SouthwestPriceFrom $219Free CancellationRating
8.0
4,244 reviews
Search Southwest flights
American AirlinesPriceFrom $257Free CancellationRating
7.2
10,000 reviews
Search American 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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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
San Juan Isla Grande Airport
San Juan Luis Munoz Marin Intl Airport