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Cheap flights from Porto to St. Louis from $379

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Porto to St. Louis departing on 4/22. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Find the cheapest flights from Porto to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
12:00 pm - 11:11 pm
OPO
-
STL
17h 11m
2 stops
United Airlines Logo
9:10 am - 9:45 am
STL
-
OPO
18h 35m
2 stops
$895United Airlines
Wed, Apr 1 - Sun, Apr 5
United Airlines Logo
12:35 pm - 11:57 pm
OPO
-
STL
17h 22m
1 stop
United Airlines Logo
6:15 am - 9:45 am
STL
-
OPO
21h 30m
1 stop
$919United Airlines
Wed, Apr 1 - Sun, Apr 5
American Airlines Logo
8:20 am - 10:17 pm
OPO
-
STL
19h 57m
2 stops
American Airlines Logo
11:45 am - 11:45 am
STL
-
OPO
18h 00m
2 stops
$1,145American Airlines
Fri, May 1 - Tue, May 5
American Airlines Logo
8:20 am - 7:33 pm
OPO
-
STL
17h 13m
2 stops
American Airlines Logo
11:45 am - 11:45 am
STL
-
OPO
18h 00m
2 stops
$1,151American Airlines
Fri, May 1 - Tue, May 5
Multiple Airlines Logo
4:35 pm - 3:25 pm
OPO
-
STL
28h 50m
3 stops
Multiple Airlines Logo
4:05 pm - 3:40 pm
STL
-
OPO
17h 35m
2 stops
$1,413Multiple Airlines
Wed, Apr 1 - Sun, Apr 5
Multiple Airlines Logo
5:45 pm - 3:25 pm
OPO
-
STL
27h 40m
3 stops
Multiple Airlines Logo
4:05 pm - 7:50 am
STL
-
OPO
33h 45m
3 stops
$1,692Multiple Airlines
Wed, Apr 1 - Sun, Apr 5

Lufthansa flights from Porto to St. Louis

Our best Lufthansa deals on Porto to St. Louis flight tickets
Lufthansa
Mar 22
OPO12:35 pmPorto
16h 16m
1 stop
STL11:51 pmLambert-St Louis
Mar 25
STL11:28 amLambert-St Louis
17h 02m
1 stop
OPO9:30 amPorto
$1,854
Lufthansa
Mar 22
OPO6:15 amPorto
21h 44m
2 stops
STL10:59 pmLambert-St Louis
Mar 25
STL11:28 amLambert-St Louis
17h 02m
1 stop
OPO9:30 amPorto
$1,863
Lufthansa
Mar 24
OPO4:15 pmPorto
27h 40m
1 stop
STL2:55 pmLambert-St Louis
Mar 26
STL11:28 amLambert-St Louis
17h 02m
1 stop
OPO9:30 amPorto
$1,940

United Airlines flights from Porto to St. Louis

Our best United Airlines deals on Porto to St. Louis flight tickets
United Airlines
Apr 1
OPO12:00 pmPorto
17h 11m
2 stops
STL11:11 pmLambert-St Louis
Apr 5
STL9:10 amLambert-St Louis
18h 35m
2 stops
OPO9:45 amPorto
$895
United Airlines
Apr 1
OPO12:35 pmPorto
17h 22m
1 stop
STL11:57 pmLambert-St Louis
Apr 5
STL6:15 amLambert-St Louis
21h 30m
1 stop
OPO9:45 amPorto
$919
United Airlines
Mar 23
OPO6:00 amPorto
20h 07m
2 stops
STL9:07 pmLambert-St Louis
Mar 26
STL9:00 amLambert-St Louis
19h 30m
2 stops
OPO9:30 amPorto
$1,532

momondo Fare Finder

 
Customize your flight search to find flights from Porto to St. Louis 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 March 20, 2026.
Use the filters below to find and compare flights from Porto to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 4/1

12:00 pm-11:11 pm

2 stops17h 11m

Lambert-St Louis

Sun 4/5

9:10 am-9:45 am

2 stops18h 35m

$895

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 4/1

12:35 pm-11:57 pm

1 stop17h 22m

Lambert-St Louis

Sun 4/5

6:15 am-9:45 am

1 stop21h 30m

$919

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Fri 5/1

8:20 am-10:17 pm

2 stops19h 57m

Lambert-St Louis

Tue 5/5

11:45 am-11:45 am

2 stops18h 00m

$1,145
Quickest round-trip

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Fri 5/1

8:20 am-7:33 pm

2 stops17h 13m

Lambert-St Louis

Tue 5/5

11:45 am-11:45 am

2 stops18h 00m

$1,151

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 4/1

4:35 pm-3:25 pm

3 stops28h 50m

Lambert-St Louis

Sun 4/5

4:05 pm-3:40 pm

2 stops17h 35m

$1,413

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 4/1

5:45 pm-3:25 pm

3 stops27h 40m

Lambert-St Louis

Sun 4/5

4:05 pm-7:50 am

3 stops33h 45m

$1,692
Cheapest one-way

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 4/22

7:00 am-6:50 am

3 stops53h 50m

$379

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Tue 4/21

3:55 pm-10:30 am

3 stops48h 35m

$432

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Mon 4/20

8:50 am-6:50 am

3 stops52h 00m

$482

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Tue 4/21

8:30 pm-11:19 pm

2 stops32h 49m

$511

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 16 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Porto to St. Louis

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

Can stopping save me money on Porto to St. Louis flights?

You could potentially save up to 28% on your flight if you consider stops on a Porto to St. Louis flight.

When to book flights from Porto to St. Louis

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

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

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

Fastest flight time

17h 11m

Direct flights

None
The fastest flight from Porto to St. Louis takes 17h 11m
There are no direct flights from Porto to St. Louis. There are no popular flight routes from Porto to St. Louis.
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  • How far is Porto to Lambert-St Louis by plane?

    There are 4156.0 mi between Porto and Lambert-St Louis. A reasonable flight in good conditions will take 17h 11m.

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

    Prices for flights from Porto Airport to Lambert-St Louis Airport refresh daily.

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

    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 Porto Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The necessary travel and health documents for your Lambert-St Louis Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Collinsville
Alton
St. Peters
Wentzville
Fenton
Farmington
Clayton
Edwardsville
Festus
Eureka
Litchfield
Shrewsbury
Grafton

Why use momondo?

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

It is quick and easy to find Porto to St. Louis flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to St. Louis that suits you.

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

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

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

momondo helps you find the best flight between Porto and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

Of course. momondo tracks the price of Porto to St. Louis flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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