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Cheap flights from St. Louis to Porto Alegre from $372

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 Porto Alegre departing on 3/31. 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

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Find the cheapest flights from St. Louis to Porto Alegre

Cheap round-trip flights

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Multiple Airlines Logo
STL
-
POA
5375 mimulti-stop
Multiple Airlines Logo
POA
-
STL
5375 mimulti-stop
Multiple Airlines

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Porto Alegre 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 January 29, 2026.
Use the filters below to find and compare flights from St. Louis to Porto Alegre that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPorto Alegre

STL - POA

STLPOA

Lambert-St Louis

Tue 3/31

11:27 am-8:05 am

3 stops42h 38m

$372

St. LouisPorto Alegre

STL - POA

STLPOA

Lambert-St Louis

Tue 3/31

4:51 pm-10:45 pm

2 stops27h 54m

$405

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

When to book flights from St. Louis to Porto Alegre

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

Cheap St. Louis to Porto Alegre (STL to POA) flight deals and tips

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

Fastest flight time

21h 08m

Direct flights

None
The fastest flight from St. Louis to Porto Alegre takes 21h 08m
There are no direct flights from St. Louis to Porto Alegre. There are no popular flight routes from St. Louis to Porto Alegre.
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  • How far is Lambert-St Louis to Porto Alegre Salgado Filho by plane?

    A flight from Lambert-St Louis to Porto Alegre Salgado Filho will travel around 5363.5 mi. Typically, this will take 21h 08m by plane in normal conditions.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Porto Alegre Salgado Filho Airport?

    Prices for flights from Lambert-St Louis Airport to Porto Alegre Salgado Filho Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Porto Alegre Salgado Filho Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Porto Alegre Salgado Filho 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 Porto Alegre Salgado Filho Airport.

  • What documentation or ID do you need to fly to Porto Alegre Salgado Filho Airport?

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

  • What is the most popular airline from St. Louis to Porto Alegre?

Best airlines flying from St. Louis to Porto Alegre

Compare and see reviews for airlines that fly from St. Louis to Porto Alegre with momondo
Airline
Rating
Free Cancellation
Price
LATAM AirlinesPriceFrom $1,167Free CancellationRating
7.5
1,917 reviews
Search LATAM Airlines flights

  • How do I get Price Alerts for flights from St. Louis to Porto Alegre?

    You can take advantage of momondo’s Price Alerts by first searching for your flights to St. Louis from Porto Alegre. Flight offers will be shown to you in real-time. From there you can create a Price Alert by using our on-site widget.

  • How can I save money on flights from St. Louis to Porto Alegre with momondo?

    Leverage our AI within our “Price Forecast” tool, which predicts if it’s better to book now or wait until prices decrease. You can strategically pick the best days to fly and save money on your trip by using our “Price Calendar” tool. “Explore” shows an overview of how much it costs to fly to anywhere from a selected city or airport. Our “Discover” content is a great option for travel inspiration and money-saving tips, while “Price Alerts” will update you when prices change, so you can book when fares are right.

  • How does momondo find its flight prices?

    We show prices from over 700+ competitors with a single click. With options from airlines and OTAs from across our 30 international markets, we are able to show you a diverse range of deals to create your adventure.

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Porto Alegre?

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

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

Yes. All flights to Porto Alegre 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 Porto Alegre?

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 Porto Alegre from St. Louis.

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

If you are not ready to book a flight from St. Louis to Porto Alegre now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Porto Alegre and let you know when they change.

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