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Cheap flights from St. Louis to Buenos Aires from $381

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 3/8. 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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Cheap round-trip flights

Enter your travel dates to find the best prices.
LATAM Airlines Logo
5:00 pm - 4:00 pm
STL
-
AEP
21h 00m2 stops
LATAM Airlines Logo
3:40 pm - 8:52 am
AEP
-
STL
19h 12m2 stops
$936LATAM Airlines
Tue, Mar 10 - Wed, Mar 25
LATAM Airlines Logo
5:00 pm - 9:00 am
STL
-
EZE
14h 00m1 stop
LATAM Airlines Logo
8:55 pm - 8:52 am
EZE
-
STL
13h 57m1 stop
$936LATAM Airlines
Tue, Mar 10 - Wed, Mar 25
LATAM Airlines Logo
5:00 pm - 9:35 am
STL
-
EZE
14h 35m2 stops
LATAM Airlines Logo
4:05 am - 11:42 pm
EZE
-
STL
21h 37m2 stops
$940LATAM Airlines
Tue, Mar 10 - Wed, Mar 25
United Airlines Logo
7:41 am - 8:20 am
STL
-
EZE
46h 39m2 stops
United Airlines Logo
9:05 pm - 9:07 pm
EZE
-
STL
26h 02m2 stops
$956United Airlines
Sun, Mar 8 - Tue, Mar 17
United Airlines Logo
7:41 am - 8:20 am
STL
-
EZE
46h 39m2 stops
United Airlines Logo
9:05 pm - 9:21 am
EZE
-
STL
14h 16m1 stop
$1,001United Airlines
Sun, Mar 8 - Tue, Mar 17
United Airlines Logo
7:41 am - 8:20 am
STL
-
EZE
46h 39m2 stops
United Airlines Logo
9:05 pm - 9:21 am
EZE
-
STL
14h 16m1 stop
$1,002United Airlines
Sun, Mar 8 - Tue, Mar 17
LATAM Airlines Logo
3:58 pm - 5:00 pm
STL
-
AEP
23h 02m2 stops
LATAM Airlines Logo
11:30 am - 8:52 am
AEP
-
STL
23h 22m2 stops
$1,013LATAM Airlines
Sun, Mar 8 - Tue, Mar 17
LATAM Airlines Logo
10:02 am - 9:00 am
STL
-
EZE
20h 58m1 stop
LATAM Airlines Logo
8:55 pm - 8:52 am
EZE
-
STL
13h 57m1 stop
$1,013LATAM Airlines
Sun, Mar 8 - Tue, Mar 17
LATAM Airlines Logo
11:51 am - 7:40 am
STL
-
AEP
17h 49m2 stops
LATAM Airlines Logo
5:05 pm - 10:45 am
AEP
-
STL
19h 40m2 stops
$1,018LATAM Airlines
Wed, May 27 - Mon, Jun 8
LATAM Airlines Logo
1:30 pm - 9:45 am
STL
-
EZE
18h 15m1 stop
LATAM Airlines Logo
7:35 am - 7:12 pm
EZE
-
STL
37h 37m3 stops
$1,021LATAM Airlines
Wed, May 27 - Mon, Jun 8

United Airlines flights from St. Louis to Buenos Aires

Our best United Airlines deals on St. Louis to Buenos Aires flight tickets
United Airlines
Mar 8
STL7:41 amLambert-St Louis
46h 39m
2 stops
EZE8:20 amBuenos Aires Ministro Pistarini
Mar 17
EZE9:05 pmBuenos Aires Ministro Pistarini
26h 02m
2 stops
STL9:07 pmLambert-St Louis
$956
Find similar
United Airlines
Mar 8
STL7:41 amLambert-St Louis
46h 39m
2 stops
EZE8:20 amBuenos Aires Ministro Pistarini
Mar 17
EZE9:05 pmBuenos Aires Ministro Pistarini
14h 16m
1 stop
STL9:21 amLambert-St Louis
$1,001
Find similar
United Airlines
Mar 8
STL7:41 amLambert-St Louis
46h 39m
2 stops
EZE8:20 amBuenos Aires Ministro Pistarini
Mar 17
EZE9:05 pmBuenos Aires Ministro Pistarini
14h 16m
1 stop
STL9:21 amLambert-St Louis
$1,002
Find similar

Air Canada flights from St. Louis to Buenos Aires

Our best Air Canada deals on St. Louis to Buenos Aires flight tickets
Air Canada
May 26
STL7:30 amLambert-St Louis
29h 00m
3 stops
EZE2:30 pmBuenos Aires Ministro Pistarini
Jun 6
EZE4:35 pmBuenos Aires Ministro Pistarini
29h 30m
2 stops
STL8:05 pmLambert-St Louis
$1,229
Find similar
Air Canada
Dec 18
STL4:05 pmLambert-St Louis
22h 15m
2 stops
EZE5:20 pmBuenos Aires Ministro Pistarini
Dec 20
EZE4:45 pmBuenos Aires Ministro Pistarini
29h 33m
3 stops
STL7:18 pmLambert-St Louis
$3,535
Find similar
Air Canada
Dec 19
STL6:30 amLambert-St Louis
29h 40m
3 stops
EZE3:10 pmBuenos Aires Ministro Pistarini
Dec 21
EZE4:45 pmBuenos Aires Ministro Pistarini
25h 44m
2 stops
STL3:29 pmLambert-St Louis
$4,274
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 December 16, 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 - AEP

STLAEP

Lambert-St Louis

Tue 3/10

5:00 pm-4:00 pm

2 stops21h 00m

Buenos Aires Jorge Newbery

Wed 3/25

3:40 pm-8:52 am

2 stops19h 12m

$936

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Tue 3/10

5:00 pm-9:00 am

1 stop14h 00m

Buenos Aires Ministro Pistarini

Wed 3/25

8:55 pm-8:52 am

1 stop13h 57m

$936

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Tue 3/10

5:00 pm-9:35 am

2 stops14h 35m

Buenos Aires Ministro Pistarini

Wed 3/25

4:05 am-11:42 pm

2 stops21h 37m

$940

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 3/8

7:41 am-8:20 am

2 stops46h 39m

Buenos Aires Ministro Pistarini

Tue 3/17

9:05 pm-9:07 pm

2 stops26h 02m

$956

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 3/8

7:41 am-8:20 am

2 stops46h 39m

Buenos Aires Ministro Pistarini

Tue 3/17

9:05 pm-9:21 am

1 stop14h 16m

$1,001

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 3/8

7:41 am-8:20 am

2 stops46h 39m

Buenos Aires Ministro Pistarini

Tue 3/17

9:05 pm-9:21 am

1 stop14h 16m

$1,002

St. LouisBuenos Aires

STL - AEP

STLAEP

Lambert-St Louis

Sun 3/8

3:58 pm-5:00 pm

2 stops23h 02m

Buenos Aires Jorge Newbery

Tue 3/17

11:30 am-8:52 am

2 stops23h 22m

$1,013

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Sun 3/8

10:02 am-9:00 am

1 stop20h 58m

Buenos Aires Ministro Pistarini

Tue 3/17

8:55 pm-8:52 am

1 stop13h 57m

$1,013

St. LouisBuenos Aires

STL - AEP

STLAEP

Lambert-St Louis

Wed 5/27

11:51 am-7:40 am

2 stops17h 49m

Buenos Aires Jorge Newbery

Mon 6/8

5:05 pm-10:45 am

2 stops19h 40m

$1,018

St. LouisBuenos Aires

STL - EZE

STLEZE

Lambert-St Louis

Wed 5/27

1:30 pm-9:45 am

1 stop18h 15m

Buenos Aires Ministro Pistarini

Mon 6/8

7:35 am-7:12 pm

3 stops37h 37m

$1,021

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 Buenos Aires from

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 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

Fastest flight time

14h 13m

Direct flights

None
The fastest flight from St. Louis to Buenos Aires takes 14h 13m
There are no direct flights from St. Louis to Buenos Aires. There are no popular flight routes from St. Louis to Buenos Aires.
Search flight deals

  • 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 14h 13m 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
DeltaPriceFrom $1,025Free CancellationRating
7.9
8,008 reviews
Search Delta 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