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Cheap flights from Porto to St. Louis from $538

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 9/24. 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

Find the cheapest flights from Porto to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Lufthansa Logo
6:00 am - 7:11 pmOPO  Porto-STL Lambert-St Louis
19h 11m2 stops Frankfurt am Main Washington, D.C. Dulles Intl
Lufthansa Logo
12:30 pm - 9:45 amSTL  Lambert-St Louis-OPO Porto
15h 15m1 stop Newark
$964Lufthansa
Wed, Sep 2 - Sun, Sep 6
Lufthansa Logo
6:00 am - 7:11 pmOPO  Porto-STL Lambert-St Louis
19h 11m2 stops Frankfurt am Main Washington, D.C. Dulles Intl
Lufthansa Logo
6:54 pm - 10:55 pmSTL  Lambert-St Louis-OPO Porto
22h 01m2 stops Chicago O'Hare Intl Frankfurt am Main
$975Lufthansa
Wed, Sep 2 - Sun, Sep 6
Lufthansa Logo
12:35 pm - 11:38 pmOPO  Porto-STL Lambert-St Louis
17h 03m1 stop Newark
Lufthansa Logo
12:30 pm - 6:55 amSTL  Lambert-St Louis-OPO Porto
12h 25m1 stop Newark
$987Lufthansa
Wed, Sep 2 - Sun, Sep 6
American Airlines Logo
8:20 am - 6:34 pmOPO  Porto-STL Lambert-St Louis
16h 14m2 stops Madrid Barajas Charlotte Douglas
American Airlines Logo
6:00 am - 11:45 amSTL  Lambert-St Louis-OPO Porto
23h 45m2 stops Philadelphia Madrid Barajas
$1,003American Airlines
Sat, Jan 16 - Wed, Jan 20
American Airlines Logo
8:20 am - 6:34 pmOPO  Porto-STL Lambert-St Louis
16h 14m2 stops Madrid Barajas Charlotte Douglas
American Airlines Logo
6:00 am - 11:45 amSTL  Lambert-St Louis-OPO Porto
23h 45m2 stops Philadelphia Madrid Barajas
$1,004American Airlines
Sat, Jan 16 - Wed, Jan 20
Delta Logo
5:00 am - 5:38 pmOPO  Porto-STL Lambert-St Louis
18h 38m2 stops Amsterdam Schiphol Detroit Metropolitan Wayne County
Delta Logo
5:34 pm - 3:25 pmSTL  Lambert-St Louis-OPO Porto
15h 51m2 stops Minneapolis St Paul Paris Charles de Gaulle
$1,163Delta
Fri, Aug 21 - Tue, Aug 25
United Airlines Logo
9:00 am - 11:38 pmOPO  Porto-STL Lambert-St Louis
20h 38m1 stop Newark
United Airlines Logo
12:59 pm - 9:45 amSTL  Lambert-St Louis-OPO Porto
14h 46m2 stops Chicago O'Hare Intl Newark
$1,169United Airlines
Fri, Aug 21 - Tue, Aug 25
Lufthansa Logo
12:35 pm - 11:38 pmOPO  Porto-STL Lambert-St Louis
17h 03m1 stop Newark
Lufthansa Logo
12:27 pm - 6:15 amSTL  Lambert-St Louis-OPO Porto
11h 48m1 stop Newark
$1,169Lufthansa
Fri, Aug 21 - Tue, Aug 25
United Airlines Logo
12:35 pm - 11:38 pmOPO  Porto-STL Lambert-St Louis
17h 03m1 stop Newark
United Airlines Logo
4:50 pm - 9:45 amSTL  Lambert-St Louis-OPO Porto
10h 55m1 stop Newark
$1,172United Airlines
Fri, Aug 21 - Tue, Aug 25
American Airlines Logo
12:25 pm - 11:42 pmOPO  Porto-STL Lambert-St Louis
17h 17m2 stops Madrid Barajas Dallas/Fort Worth
American Airlines Logo
1:25 pm - 11:45 amSTL  Lambert-St Louis-OPO Porto
16h 20m2 stops Chicago O'Hare Intl Madrid Barajas
$1,186American Airlines
Fri, Aug 21 - Tue, Aug 25

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Lufthansa flights from Porto to St. Louis

Our best Lufthansa deals on Porto to St. Louis flight tickets
Lufthansa
Sep 2
OPO6:00 amPorto
19h 11m
2 stops
STL7:11 pmLambert-St Louis
Sep 6
STL12:30 pmLambert-St Louis
15h 15m
1 stop
OPO9:45 amPorto
$964
Lufthansa
Sep 2
OPO6:00 amPorto
19h 11m
2 stops
STL7:11 pmLambert-St Louis
Sep 6
STL6:54 pmLambert-St Louis
22h 01m
2 stops
OPO10:55 pmPorto
$975
Lufthansa
Sep 2
OPO12:35 pmPorto
17h 03m
1 stop
STL11:38 pmLambert-St Louis
Sep 6
STL12:30 pmLambert-St Louis
12h 25m
1 stop
OPO6:55 amPorto
$987

American Airlines flights from Porto to St. Louis

Our best American Airlines deals on Porto to St. Louis flight tickets
American Airlines
Jan 16
OPO8:20 amPorto
16h 14m
2 stops
STL6:34 pmLambert-St Louis
Jan 20
STL6:00 amLambert-St Louis
23h 45m
2 stops
OPO11:45 amPorto
$1,003
American Airlines
Jan 16
OPO8:20 amPorto
16h 14m
2 stops
STL6:34 pmLambert-St Louis
Jan 20
STL6:00 amLambert-St Louis
23h 45m
2 stops
OPO11:45 amPorto
$1,004
American Airlines
Aug 21
OPO12:25 pmPorto
17h 17m
2 stops
STL11:42 pmLambert-St Louis
Aug 25
STL1:25 pmLambert-St Louis
16h 20m
2 stops
OPO11:45 amPorto
$1,186

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 August 7, 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 Porto - STL Lambert-St Louis

OPOSTL

Porto

Wed 9/2

6:00 am-7:11 pm

2 stops19h 11m

Lambert-St Louis

Sun 9/6

12:30 pm-9:45 am

1 stop15h 15m

$964

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Wed 9/2

6:00 am-7:11 pm

2 stops19h 11m

Lambert-St Louis

Sun 9/6

6:54 pm-10:55 pm

2 stops22h 01m

$975

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Wed 9/2

12:35 pm-11:38 pm

1 stop17h 03m

Lambert-St Louis

Sun 9/6

12:30 pm-6:55 am

1 stop12h 25m

$987

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Sat 1/16

8:20 am-6:34 pm

2 stops16h 14m

Lambert-St Louis

Wed 1/20

6:00 am-11:45 am

2 stops23h 45m

$1,003

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Sat 1/16

8:20 am-6:34 pm

2 stops16h 14m

Lambert-St Louis

Wed 1/20

6:00 am-11:45 am

2 stops23h 45m

$1,004

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Fri 8/21

5:00 am-5:38 pm

2 stops18h 38m

Lambert-St Louis

Tue 8/25

5:34 pm-3:25 pm

2 stops15h 51m

$1,163

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Fri 8/21

9:00 am-11:38 pm

1 stop20h 38m

Lambert-St Louis

Tue 8/25

12:59 pm-9:45 am

2 stops14h 46m

$1,169

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Fri 8/21

12:35 pm-11:38 pm

1 stop17h 03m

Lambert-St Louis

Tue 8/25

12:27 pm-6:15 am

1 stop11h 48m

$1,169
Quickest round-trip

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Fri 8/21

12:35 pm-11:38 pm

1 stop17h 03m

Lambert-St Louis

Tue 8/25

4:50 pm-9:45 am

1 stop10h 55m

$1,172

PortoSt. Louis

OPO Porto - STL Lambert-St Louis

OPOSTL

Porto

Fri 8/21

12:25 pm-11:42 pm

2 stops17h 17m

Lambert-St Louis

Tue 8/25

1:25 pm-11:45 am

2 stops16h 20m

$1,186

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 19 resultsSorted by cheapest first
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How to get the cheapest flight ticket from Porto to St. Louis

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

You could potentially save up to 42% 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

18h 38m

Direct flights

None
The fastest flight from Porto to St. Louis takes 18h 38m
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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Frequently asked questions about flying from Porto to St. Louis

  • 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 18h 38m.

  • 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
Fairview Heights
Hermann
St. Peters
Maryland Heights
Florissant
Collinsville
Alton
O'Fallon
Clayton
Farmington
Fenton
Wentzville
Festus
Eureka
Edwardsville
Litchfield
Grafton
Shrewsbury

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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