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Cheap flights from St. Louis to Buenos Aires from $431

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 Buenos Aires departing on 2/20. 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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Cheap round-trip flights

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LATAM Airlines Logo
10:13 am - 6:05 amSTL-EZE
16h 52m2 stops
LATAM Airlines Logo
8:00 am - 11:40 pmEZE-STL
17h 40m2 stops
$1,018LATAM Airlines
Find Deal
Wed, Feb 18 - Wed, Mar 11
LATAM Airlines Logo
6:00 am - 10:15 amSTL-EZE
25h 15m2 stops
LATAM Airlines Logo
9:55 pm - 11:40 pmEZE-STL
27h 45m2 stops
$1,022LATAM Airlines
Find Deal
Mon, Feb 16 - Sun, Mar 8
Delta Logo
7:10 am - 9:00 amSTL-EZE
22h 50m1 stop
Delta Logo
8:55 pm - 9:04 amEZE-STL
14h 09m1 stop
$1,026Delta
Find Deal
Tue, Feb 17 - Tue, Mar 10
United Airlines Logo
6:45 pm - 7:20 amSTL-EZE
33h 35m2 stops
United Airlines Logo
9:05 pm - 5:44 pmEZE-STL
22h 39m2 stops
$1,030United Airlines
Find Deal
Sun, Feb 15 - Tue, Mar 10
United Airlines Logo
4:39 pm - 7:20 amSTL-EZE
35h 41m1 stop
United Airlines Logo
10:55 pm - 4:05 pmEZE-STL
19h 10m1 stop
$1,035United Airlines
Find Deal
Sun, Feb 15 - Thu, Mar 12
LATAM Airlines Logo
4:00 pm - 9:35 amSTL-EZE
15h 35m2 stops
LATAM Airlines Logo
8:00 am - 9:04 amEZE-STL
27h 04m2 stops
$1,048LATAM Airlines
Find Deal
Sun, Mar 8 - Tue, Mar 17
LATAM Airlines Logo
7:05 pm - 5:00 pmSTL-AEP
19h 55m2 stops
LATAM Airlines Logo
5:15 pm - 11:50 amAEP-STL
20h 35m2 stops
$1,058LATAM Airlines
Find Deal
Sun, Mar 8 - Tue, Mar 17
Delta Logo
10:13 am - 9:00 amSTL-EZE
19h 47m1 stop
Delta Logo
8:55 pm - 9:04 amEZE-STL
14h 09m1 stop
$1,066Delta
Find Deal
Fri, Feb 20 - Wed, Mar 11
Multiple Airlines Logo
4:05 pm - 5:40 amSTL-AEP
34h 35m3 stops
Multiple Airlines Logo
6:15 am - 10:56 amAEP-STL
31h 41m3 stops
$1,216Multiple Airlines
Find Deal
Mon, Dec 8 - Mon, Dec 22
Multiple Airlines Logo
4:05 pm - 5:40 amSTL-AEP
34h 35m3 stops
Multiple Airlines Logo
5:10 pm - 10:56 amAEP-STL
20h 46m2 stops
$1,263Multiple Airlines
Find Deal
Mon, Dec 8 - Mon, Dec 22

LATAM Airlines flights from St. Louis to Buenos Aires

Our best LATAM Airlines deals on St. Louis to Buenos Aires flight tickets
LATAM Airlines
Feb 18
STL11:55 amLambert-St Louis
18h 05m
1 stop
EZE9:00 amBuenos Aires Ministro Pistarini
Mar 11
EZE8:55 pmBuenos Aires Ministro Pistarini
20h 06m
1 stop
STL3:01 pmLambert-St Louis
$1,018
Find similar
LATAM Airlines
Feb 16
STL6:00 amLambert-St Louis
25h 15m
2 stops
EZE10:15 amBuenos Aires Ministro Pistarini
Mar 8
EZE9:55 pmBuenos Aires Ministro Pistarini
27h 45m
2 stops
STL11:40 pmLambert-St Louis
$1,022
Find similar
LATAM Airlines
Mar 8
STL4:00 pmLambert-St Louis
15h 35m
2 stops
EZE9:35 amBuenos Aires Ministro Pistarini
Mar 17
EZE8:00 amBuenos Aires Ministro Pistarini
27h 04m
2 stops
STL9:04 amLambert-St Louis
$1,048
Find similar

Delta flights from St. Louis to Buenos Aires

Our best Delta deals on St. Louis to Buenos Aires flight tickets
Delta
Feb 17
STL7:10 amLambert-St Louis
22h 50m
1 stop
EZE9:00 amBuenos Aires Ministro Pistarini
Mar 10
EZE8:55 pmBuenos Aires Ministro Pistarini
14h 09m
1 stop
STL9:04 amLambert-St Louis
$1,026
Find similar
Delta
Feb 20
STL3:47 pmLambert-St Louis
20h 08m
2 stops
EZE2:55 pmBuenos Aires Ministro Pistarini
Mar 12
EZE11:55 pmBuenos Aires Ministro Pistarini
17h 06m
1 stop
STL3:01 pmLambert-St Louis
$1,066
Find similar
Delta
Feb 16
STL10:13 amLambert-St Louis
19h 47m
1 stop
EZE9:00 amBuenos Aires Ministro Pistarini
Mar 8
EZE8:55 pmBuenos Aires Ministro Pistarini
28h 45m
1 stop
STL11:40 pmLambert-St Louis
$1,074
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Buenos Aires 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 November 20, 2025.
Use the filters below to find and compare flights from St. Louis to Buenos Aires that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Wed 2/18

10:13 am-6:05 am

2 stops16h 52m

Buenos Aires Ministro Pistarini

Wed 3/11

8:00 am-11:40 pm

2 stops17h 40m

$1,018

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Mon 2/16

6:00 am-10:15 am

2 stops25h 15m

Buenos Aires Ministro Pistarini

Sun 3/8

9:55 pm-11:40 pm

2 stops27h 45m

$1,022

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Tue 2/17

7:10 am-9:00 am

1 stop22h 50m

Buenos Aires Ministro Pistarini

Tue 3/10

8:55 pm-9:04 am

1 stop14h 09m

$1,026

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 2/15

6:45 pm-7:20 am

2 stops33h 35m

Buenos Aires Ministro Pistarini

Tue 3/10

9:05 pm-5:44 pm

2 stops22h 39m

$1,030

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 2/15

4:39 pm-7:20 am

1 stop35h 41m

Buenos Aires Ministro Pistarini

Thu 3/12

10:55 pm-4:05 pm

1 stop19h 10m

$1,035

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 3/8

4:00 pm-9:35 am

2 stops15h 35m

Buenos Aires Ministro Pistarini

Tue 3/17

8:00 am-9:04 am

2 stops27h 04m

$1,048

St. LouisBuenos Aires

STL - AEP

STLAEP

Lambert-St Louis

Sun 3/8

7:05 pm-5:00 pm

2 stops19h 55m

Buenos Aires Jorge Newbery

Tue 3/17

5:15 pm-11:50 am

2 stops20h 35m

$1,058

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Fri 2/20

10:13 am-9:00 am

1 stop19h 47m

Buenos Aires Ministro Pistarini

Wed 3/11

8:55 pm-9:04 am

1 stop14h 09m

$1,066

St. LouisBuenos Aires

STL - AEP

STLAEP

Lambert-St Louis

Mon 12/8

4:05 pm-5:40 am

3 stops34h 35m

Buenos Aires Jorge Newbery

Mon 12/22

6:15 am-10:56 am

3 stops31h 41m

$1,216

St. LouisBuenos Aires

STL - AEP

STLAEP

Lambert-St Louis

Mon 12/8

4:05 pm-5:40 am

3 stops34h 35m

Buenos Aires Jorge Newbery

Mon 12/22

5:10 pm-10:56 am

2 stops20h 46m

$1,263

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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How to get the cheapest flight ticket from St. Louis to Buenos Aires

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 Buenos Aires?

What is the cheapest month to fly to Buenos Aires?

The cheapest month to fly to Buenos Aires from St. Louis is in September. Flight prices, which tend to average around $1,056, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of September, then book flights to Buenos Aires from St. Louis during October instead. Flights to Buenos Aires in October, while not as cheap as those in September, still average around $1,160.

What is the cheapest day to depart on your flight to Buenos Aires?

On average, the least expensive day to fly to Buenos Aires from St. Louis is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as $1,163. However, this price may fluctuate depending on the airline, the season, and holidays. Be sure to avoid booking your departure on a Friday as prices are generally higher than usual. According to our data, the average ticket price to Buenos Aires on Friday is $1,386.

What is the cheapest time of day to depart on your flight to Buenos Aires?

Our most recent data shows that the best time of day to fly to Buenos Aires is in the evening. Flights from St. Louis to Buenos Aires during this time can be as low as $1,153. Try not to purchase tickets in the morning because they tend to be around $1,368. Of course, these prices can vary depending on the time of year and what airport you fly to.

When to book flights from St. Louis to Buenos Aires

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

Cheap St. Louis to Buenos Aires (STL to BUE) flight deals and tips

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

Direct flights

None
There are no direct flights from St. Louis to Buenos Aires. There are no popular flight routes from St. Louis to Buenos Aires.
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  • How far is Lambert-St Louis to Buenos Aires by plane?

    The straight-line distance from Lambert-St Louis to Buenos Aires is 5450.9 mi. Typically, this will take 12h 48m by plane in normal conditions.

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

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

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

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

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Buenos Aires.

  • What documentation or ID do you need to fly to Buenos Aires?

    The travel and health documents required for your trip to Buenos Aires can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Buenos Aires. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular airline from St. Louis to Buenos Aires?

Best airlines flying from St. Louis to Buenos Aires

Compare and see reviews for airlines that fly from St. Louis to Buenos Aires with momondo
Airline
Rating
Free Cancellation
Price
American AirlinesPriceFrom $1,023Free CancellationRating
7.2
11,047 reviews
Search American Airlines flights
DeltaPriceFrom $1,025Free CancellationRating
7.9
8,002 reviews
Search Delta flights
United AirlinesPriceFrom $1,081Free CancellationRating
7.4
9,029 reviews
Search United Airlines flights

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Buenos Aires?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Buenos Aires from St. Louis.

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

Yes. All flights to Buenos Aires from St. Louis on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from St. Louis to Buenos Aires?

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 Buenos Aires from St. Louis.

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

Yes momondo offers price alerts on flights to Buenos Aires 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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Find better results for your trip to Argentina

Fly into one of these airports located in Buenos Aires

Airports listed have a maximum distance of 17.0 mi from Buenos Aires
Buenos Aires Jorge Newbery Airport
Buenos Aires Ministro Pistarini Airport