Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from St. Louis to Porto from $493

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Porto departing on 2/4. 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

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from St. Louis to Porto

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
9:59 am - 10:30 am
STL
-
OPO
18h 31m2 stops
Multiple Airlines Logo
4:10 pm - 5:42 pm
OPO
-
STL
31h 32m2 stops
$493Multiple Airlines
Rabu, Feb 4 - Rabu, Feb 11
United Airlines Logo
8:20 am - 3:25 pm
STL
-
OPO
25h 05m2 stops
United Airlines Logo
12:30 pm - 2:30 pm
OPO
-
STL
56h 00m2 stops
$527United Airlines
Rabu, Feb 4 - Ahad, Feb 8
Lufthansa Logo
1:15 pm - 10:25 pm
STL
-
OPO
27h 10m2 stops
Lufthansa Logo
6:00 am - 11:59 pm
OPO
-
STL
23h 59m2 stops
$687Lufthansa
Jumaat, Jan 16 - Selasa, Jan 20
Lufthansa Logo
3:50 pm - 11:40 am
STL
-
OPO
13h 50m1 stop
Lufthansa Logo
6:00 am - 10:58 pm
OPO
-
STL
22h 58m2 stops
$688Lufthansa
Jumaat, Jan 16 - Selasa, Jan 20
Lufthansa Logo
3:50 pm - 11:40 am
STL
-
OPO
13h 50m1 stop
Lufthansa Logo
12:30 pm - 1:55 pm
OPO
-
STL
31h 25m1 stop
$718Lufthansa
Jumaat, Jan 16 - Selasa, Jan 20
Lufthansa Logo
3:50 pm - 11:40 am
STL
-
OPO
13h 50m1 stop
Lufthansa Logo
6:00 am - 1:55 pm
OPO
-
STL
13h 55m1 stop
$730Lufthansa
Rabu, Jan 14 - Ahad, Jan 18
Lufthansa Logo
3:50 pm - 11:40 am
STL
-
OPO
13h 50m1 stop
Lufthansa Logo
12:30 pm - 10:58 pm
OPO
-
STL
40h 28m2 stops
$733Lufthansa
Rabu, Jan 14 - Ahad, Jan 18
Lufthansa Logo
6:40 pm - 11:40 am
STL
-
OPO
35h 00m2 stops
Lufthansa Logo
12:30 pm - 10:58 pm
OPO
-
STL
40h 28m2 stops
$737Lufthansa
Rabu, Jan 14 - Ahad, Jan 18
Delta Logo
5:00 pm - 10:30 am
STL
-
OPO
11h 30m1 stop
Delta Logo
5:00 am - 4:49 pm
OPO
-
STL
17h 49m2 stops
$791Delta
Isnin, Mei 25 - Khamis, Jun 4
Multiple Airlines Logo
5:00 pm - 10:30 am
STL
-
OPO
11h 30m1 stop
Multiple Airlines Logo
5:00 am - 4:45 pm
OPO
-
STL
17h 45m2 stops
$792Multiple Airlines
Isnin, Mei 25 - Khamis, Jun 4

Delta flights from St. Louis to Porto

Our best Delta deals on St. Louis to Porto flight tickets
Delta
May 25
STL5:00 pmLambert-St Louis
11h 30m
1 stop
OPO10:30 amPorto
Jun 4
OPO5:00 amPorto
17h 49m
2 stops
STL4:49 pmLambert-St Louis
$791
Find similar
Delta
May 25
STL5:30 pmLambert-St Louis
15h 55m
2 stops
OPO3:25 pmPorto
Jun 4
OPO5:00 amPorto
21h 31m
2 stops
STL8:31 pmLambert-St Louis
$796
Find similar
Delta
Jun 3
STL5:00 pmLambert-St Louis
16h 25m
2 stops
OPO3:25 pmPorto
Jun 17
OPO5:00 amPorto
17h 49m
2 stops
STL4:49 pmLambert-St Louis
$846
Find similar

American Airlines flights from St. Louis to Porto

Our best American Airlines deals on St. Louis to Porto flight tickets
American Airlines
May 17
STL2:19 pmLambert-St Louis
15h 26m
2 stops
OPO11:45 amPorto
May 30
OPO8:20 amPorto
17h 42m
2 stops
STL8:02 pmLambert-St Louis
$1,028
Find similar
American Airlines
Mar 13
STL11:22 amLambert-St Louis
15h 18m
2 stops
OPO7:40 amPorto
Mar 21
OPO12:25 pmPorto
28h 04m
2 stops
STL11:29 amLambert-St Louis
$1,466
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Porto 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 Disember 23, 2025.
Use the filters below to find and compare flights from St. Louis to Porto that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Rabu 2/4

9:59 am-10:30 am

2 stops18h 31m

Porto

Rabu 2/11

4:10 pm-5:42 pm

2 stops31h 32m

$493

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Rabu 2/4

8:20 am-3:25 pm

2 stops25h 05m

Porto

Ahad 2/8

12:30 pm-2:30 pm

2 stops56h 00m

$527

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Jumaat 1/16

1:15 pm-10:25 pm

2 stops27h 10m

Porto

Selasa 1/20

6:00 am-11:59 pm

2 stops23h 59m

$687

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Jumaat 1/16

3:50 pm-11:40 am

1 stop13h 50m

Porto

Selasa 1/20

6:00 am-10:58 pm

2 stops22h 58m

$688

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Jumaat 1/16

3:50 pm-11:40 am

1 stop13h 50m

Porto

Selasa 1/20

12:30 pm-1:55 pm

1 stop31h 25m

$718

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Rabu 1/14

3:50 pm-11:40 am

1 stop13h 50m

Porto

Ahad 1/18

6:00 am-1:55 pm

1 stop13h 55m

$730

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Rabu 1/14

3:50 pm-11:40 am

1 stop13h 50m

Porto

Ahad 1/18

12:30 pm-10:58 pm

2 stops40h 28m

$733

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Rabu 1/14

6:40 pm-11:40 am

2 stops35h 00m

Porto

Ahad 1/18

12:30 pm-10:58 pm

2 stops40h 28m

$737

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Isnin 5/25

5:00 pm-10:30 am

1 stop11h 30m

Porto

Khamis 6/4

5:00 am-4:49 pm

2 stops17h 49m

$791

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Isnin 5/25

5:00 pm-10:30 am

1 stop11h 30m

Porto

Khamis 6/4

5:00 am-4:45 pm

2 stops17h 45m

$792

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to Porto from

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

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 day to depart on your flight to Porto?

The cheapest day to depart on your flight to Porto is on a Thursday when prices can be found for as low as $752. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Friday because tickets tend to average around $1,465. These prices are subject to change though, so be sure to set up a Price Alert for flights to Porto.

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

At noon is the cheapest time of day to fly from St. Louis to Porto when you can find flight prices for as low as $752. Flying to Porto at noon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the afternoon when prices are $1,170 on average. Flights to Porto from St. Louis in the afternoon are generally more expensive because this time of day is more convenient for travelers’ schedules.

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

You could potentially save up to 35% on your flight if you consider stops on a St. Louis to Porto flight.

When to book flights from St. Louis to Porto

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

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

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

Fastest flight time

11h 30m

Direct flights

None
The fastest flight from St. Louis to Porto takes 11h 30m
There are no direct flights from St. Louis to Porto. There are no popular flight routes from St. Louis to Porto.
Search flight deals

  • How far is Lambert-St Louis to Porto by plane?

    There are 4156.0 mi between Lambert-St Louis and Porto. A reasonable flight in good conditions will take 11h 30m.

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

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

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

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

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

    The travel and health documents you'll need for your trip to Porto 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 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?

Best airlines flying from St. Louis to Porto

Compare and see reviews for airlines that fly from St. Louis to Porto with momondo
Airline
Rating
Free Cancellation
Price
LufthansaPriceFrom $520Free CancellationRating
6.8
7,646 reviews
Search Lufthansa flights
DeltaPriceFrom $713Free CancellationRating
7.9
8,013 reviews
Search Delta flights
United AirlinesPriceFrom $760Free CancellationRating
7.4
9,102 reviews
Search United Airlines flights
Air CanadaPriceFrom $787Free CancellationRating
7.1
10,551 reviews
Search Air Canada flights

Traveling to a place near Porto?

Book flights to Porto if you plan to visit one of these locations
Vila Nova de Gaia
Coimbra
Braga
Aveiro
Matosinhos
Guimarães
Esposende
Lamego
Chaves
Viseu
Espinho
Arcos de Valdevez
Pinhao
Ponte de Lima
Curia
Penafiel
Mesao Frio
Mira
Baiao

Why use momondo?

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

Finding the right flight to Porto from St. Louis is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Porto quick and easy, saving you time and money.

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

All flight searches from St. Louis to Porto on momondo can be filtered to show those which offer flexible booking policies.

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Porto.

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

Price alerts on flights to Porto from St. Louis are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your Porto trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Khamis 1/22
Khamis 1/29
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Portugal