How long is the flight from St. Louis to Porto?

There are many flights that can get you from St. Louis to Porto in 17h 02m. Fly via Delta, Lufthansa, or United Airlines to get the fastest option. Airlines will cover a distance of 4154 mi. Both multi-stop and nonstop flights can be found to your destination and back.

What are the cheapest airlines flying from St. Louis to Porto round-trip?

Lufthansa, at $549, was found to be the cheapest airline from St. Louis to Porto. An alternate airline flying to your destination would be United Airlines. Users have found that Lufthansa is 48% cheaper than the other options available to this destination.

In terms of precipitation, rainfall in Porto ranges from 0.7 - 7.7 inches per month. December is typically the wettest month, when rainfall can reach 7.7 in. July is typically the driest time to visit Porto when rainfall is around 0.7 in.

If weather is an important factor for your trip to Porto, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 68.0 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 48.2 F).

Most accurate provider : When it comes to deals on St. Louis-Porto flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on St. Louis-Porto flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from St. Louis-Porto flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on St. Louis-Porto flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Porto flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Can I find deals for flights from St. Louis to Porto that include hotel bookings?

Yes. In addition to deals on St. Louis to Porto flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from St. Louis to Porto?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Porto.

Can I find deals for business class flights from St. Louis to Porto?

Yes. Cheapflights offers flight deals from St. Louis to Porto by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$492+ Flights from St. Louis to Porto

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1. Tell us where you want to go

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2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

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Cheap flight deals from St. Louis to Porto

Most accurate provider	eDreams 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$492 (Delta)
Popular in	July
Cheapest in	November
Average price	$612

Provider with most accurate pricing for Lambert-St Louis-Porto flight deals.

Search Deals

Provider most trusted by Cheapflights users for Lambert-St Louis-Porto flights.

Search Deals

From Lambert-St Louis to Porto

Search Deals

Highest demand for flights based on searches. 18% potential increase in price ($241 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($34 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in November 2025

Search Deals

Find flight deals from St. Louis to Porto

Cheapest flights from St. Louis to Porto
Explore the most affordable flight options available from St. Louis to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 20, 2025.

Thu 12/119:30 amSTL - OPO

2 stops16h 10mIberia

Thu 12/188:20 amOPO - STL

2 stops31h 11mIberia

Deal found 11/18

$819

Thu 12/111:00 pmSTL - OPO

2 stops27h 25mLufthansa

Thu 12/1812:30 pmOPO - STL

1 stop31h 25mLufthansa

Deal found 11/18

$1,481

Mon 12/292:50 pmSTL - OPO

2 stops34h 50mIberia

Sat 1/38:20 amOPO - STL

2 stops31h 11mIberia

Deal found 11/19

$2,318

Mon 12/299:55 amSTL - OPO

2 stops19h 45mUnited Airlines

Sat 1/312:30 pmOPO - STL

1 stop31h 25mUnited Airlines

Deal found 11/19

$3,003

Best flights from St. Louis to Porto
Discover carefully curated flight deals from St. Louis to Porto that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated November 20, 2025.

Fri 2/66:00 amSTL - OPO

2 stops22h 30mDelta

Tue 2/106:05 amOPO - STL

2 stops20h 38mDelta

Deal found 11/18

$492

Tue 3/1011:28 amSTL - OPO

1 stop17h 02mLufthansa

Wed 3/186:00 amOPO - STL

1 stop13h 55mLufthansa

Deal found 11/17

$574

Wed 3/1111:25 amSTL - OPO

2 stops17h 05mUnited Airlines

Wed 3/186:00 amOPO - STL

1 stop13h 55mUnited Airlines

Deal found 11/17

$578

Mon 3/165:41 pmSTL - OPO

1 stop10h 49mUnited Airlines

Tue 3/246:00 amOPO - STL

2 stops20h 00mUnited Airlines

Deal found 11/17

$583

Tue 3/1010:45 amSTL - OPO

2 stops18h 45mDelta

Thu 3/1911:15 amOPO - STL

2 stops26h 49mDelta

Deal found 11/17

$591

Wed 3/1111:28 amSTL - OPO

2 stops22h 57mLufthansa

Thu 3/1912:35 pmOPO - STL

1 stop16h 16mLufthansa

Deal found 11/17

$614

Wed 3/1111:25 amSTL - OPO

2 stops17h 05mUnited Airlines

Tue 3/246:00 amOPO - STL

2 stops20h 50mUnited Airlines

Deal found 11/17

$588

Mon 3/167:05 pmSTL - OPO

2 stops15h 20mDelta

Tue 3/2411:15 amOPO - STL

2 stops26h 49mDelta

Deal found 11/17

$597

Tue 3/108:30 amSTL - OPO

2 stops20h 00mUnited Airlines

Tue 3/246:00 amOPO - STL

2 stops20h 00mUnited Airlines

Deal found 11/17

$588

Wed 3/1111:25 amSTL - OPO

2 stops17h 05mUnited Airlines

Thu 3/1912:35 pmOPO - STL

2 stops25h 46mUnited Airlines

Deal found 11/17

$598

Last-minute flights from St. Louis to Porto
Discover last-minute flight deals from St. Louis to Porto. Data last updated November 20, 2025 and is based on user searches.

Thu 12/119:30 amSTL - OPO

2 stops16h 10mIberia

Thu 12/188:20 amOPO - STL

2 stops31h 11mIberia

Deal found 11/18

$819

Thu 12/111:00 pmSTL - OPO

2 stops27h 25mLufthansa

Thu 12/1812:30 pmOPO - STL

1 stop31h 25mLufthansa

Deal found 11/18

$1,481

Mon 12/292:50 pmSTL - OPO

2 stops34h 50mIberia

Sat 1/38:20 amOPO - STL

2 stops31h 11mIberia

Deal found 11/19

$2,318

Mon 12/299:55 amSTL - OPO

2 stops19h 45mUnited Airlines

Sat 1/312:30 pmOPO - STL

1 stop31h 25mUnited Airlines

Deal found 11/19

$3,003

One-way flights from St. Louis to Porto
Search for one-way flight options from St. Louis to Porto. Find affordable one-way fares based on user searches. Data last updated November 20, 2025.

Thu 5/1411:14 amSTL - OPO

2 stops18h 31mIberia

Deal found 11/18

$1,426

Thu 5/1411:45 amSTL - OPO

1 stop16h 00mLufthansa

Deal found 11/18

$5,887

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 2/6

6:00 am-10:30 am

2 stops22h 30m

Porto

Tue 2/10

6:05 am-8:43 pm

2 stops20h 38m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 3/10

11:28 am-9:30 am

1 stop17h 02m

Porto

Wed 3/18

6:00 am-2:55 pm

1 stop13h 55m

$574

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 3/11

11:25 am-9:30 am

2 stops17h 05m

Porto

Wed 3/18

6:00 am-2:55 pm

1 stop13h 55m

$578

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 3/16

5:41 pm-9:30 am

1 stop10h 49m

Porto

Tue 3/24

6:00 am-9:00 pm

2 stops20h 00m

$583

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 3/11

11:25 am-9:30 am

2 stops17h 05m

Porto

Tue 3/24

6:00 am-9:50 pm

2 stops20h 50m

$588

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 3/10

8:30 am-9:30 am

2 stops20h 00m

Porto

Tue 3/24

6:00 am-9:00 pm

2 stops20h 00m

$588

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 3/10

10:45 am-10:30 am

2 stops18h 45m

Porto

Thu 3/19

11:15 am-9:04 am

2 stops26h 49m

$591

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 3/16

7:05 pm-3:25 pm

2 stops15h 20m

Porto

Tue 3/24

11:15 am-9:04 am

2 stops26h 49m

$597

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 3/11

11:25 am-9:30 am

2 stops17h 05m

Porto

Thu 3/19

12:35 pm-9:21 am

2 stops25h 46m

$598

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 3/11

11:28 am-3:25 pm

2 stops22h 57m

Porto

Thu 3/19

12:35 pm-11:51 pm

1 stop16h 16m

$614

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/17

Showing 1-10 of 12 results

Compare providers for flights from St. Louis to Porto

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Porto in November.

Provider	Price Accuracy	Trust Score*
FlightHub	Price Accuracy3 stars	Trust Score*1 star
eDreams	Price Accuracy3 stars	Trust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on St. Louis-Porto flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on St. Louis-Porto flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from St. Louis-Porto flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on St. Louis-Porto flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Porto flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from St. Louis to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from St. Louis with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Porto

What is the cheapest time of day to fly from STL to OPO?

Unlike in the evening, when flights are generally more expensive, you can save up to 39% on flights from St. Louis to Porto by exploring options for tickets at noon.

Reviews of airlines servicing Porto

Read reviews from past customers who have flown United Airlines and Lufthansa from St. Louis to Porto. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

United Airlines

7.4

Good

9,028 reviews

Reviews

1 / 20

2.0

Mediocre

Sebrena,Oct 2025

IAH - RSW

The worst that I have ever experienced in my life so bad if it was free I'm not ever going to use your Airline again I dont believe ..... very disappointed 😞 😔0000000000000

United Airlines

7.4

Good

9,028 reviews

United Airlines

7.4

Good

9,028 reviews

Reviews

1 / 20

2.0

Mediocre

Sebrena,Oct 2025

IAH - RSW

The worst that I have ever experienced in my life so bad if it was free I'm not ever going to use your Airline again I dont believe ..... very disappointed 😞 😔0000000000000

Lufthansa

6.8

Okay

7,579 reviews

United Airlines

7.4

Good

9,028 reviews

Reviews

1 / 20

2.0

Mediocre

Sebrena,Oct 2025

IAH - RSW

The worst that I have ever experienced in my life so bad if it was free I'm not ever going to use your Airline again I dont believe ..... very disappointed 😞 😔0000000000000

Related info for your journey

How long is the flight from St. Louis to Porto?
There are many flights that can get you from St. Louis to Porto in 17h 02m. Fly via Delta, Lufthansa, or United Airlines to get the fastest option. Airlines will cover a distance of 4154 mi. Both multi-stop and nonstop flights can be found to your destination and back.
What are the cheapest airlines flying from St. Louis to Porto round-trip?
Lufthansa, at $549, was found to be the cheapest airline from St. Louis to Porto. An alternate airline flying to your destination would be United Airlines. Users have found that Lufthansa is 48% cheaper than the other options available to this destination.
Can I find deals for flights from St. Louis to Porto that include hotel bookings?
Yes. In addition to deals on St. Louis to Porto flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from St. Louis to Porto?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Porto.
Can I find deals for business class flights from St. Louis to Porto?
Yes. Cheapflights offers flight deals from St. Louis to Porto by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

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Other flights to Porto

Top 2 airlines flying from St. Louis to Porto

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest$549	Average$1,214	FlexibilityNo cancel fee	On-time76%
United Airlines	Cheapest$751	Average$1,177	FlexibilityNo cancel fee	On-time69%

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$492+ Cheap flights from St. Louis (STL) to Porto (OPO)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/6. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from St. Louis to Porto with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from St. Louis to Porto

Most accurate provider

Most trusted provider

Round-trip from

Popular in

Cheapest in

Average price

Find flight deals from St. Louis to Porto

Cheapest flights from St. Louis to PortoExplore the most affordable flight options available from St. Louis to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 20, 2025.

Explore the most affordable flight options available from St. Louis to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 20, 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights from St. Louis to Porto that are best for you.

Compare providers for flights from St. Louis to Porto

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Porto in November.

Best time to book a flight from St. Louis to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from St. Louis with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Porto

What is the cheapest time of day to fly from STL to OPO?

Reviews of airlines servicing Porto

Read reviews from past customers who have flown United Airlines and Lufthansa from St. Louis to Porto. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Porto. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

How long is the flight from St. Louis to Porto?

What are the cheapest airlines flying from St. Louis to Porto round-trip?

Can I find deals for flights from St. Louis to Porto that include hotel bookings?

How can I find direct flights from St. Louis to Porto?

Can I find deals for business class flights from St. Louis to Porto?

Traveling to a place near Porto?

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for St. Louis to Porto

See prices for flight routes from nearby airports that may be better suited for you.

Top 2 airlines flying from St. Louis to Porto

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Cheapest flights from St. Louis to Porto
Explore the most affordable flight options available from St. Louis to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 20, 2025.