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

There are many flights that can get you from St. Louis to Porto in 18h 18m. Fly via Iberia, United Airlines, or British Airways 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 $520, was found to be the cheapest airline from St. Louis to Porto.Alternate airlines to your destination round-trip include Delta and United Airlines. Users have found that Lufthansa is 50% 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).

What are the most popular airlines that fly from St. Louis to Porto?

When booking a flight from St. Louis to Porto, you may want to consider flying on United Airlines, Lufthansa or Delta as they are the most popular for this route.

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

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from St. Louis to Porto as you normally would.

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.

$436+ Flights from St. Louis to Porto

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1. Tell us where you want to go

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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	$565 (Expedia)
One-way from	$424 (Lufthansa)
Popular in	January
Cheapest in	February
Average price	$1,434

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

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

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From Lambert-St Louis to Porto

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One-way flight from Lambert-St Louis to Porto

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High demand for flights, 7% potential price rise

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($39 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in January 2026

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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 enero 8, 2026.

dom. 2/227:00 amSTL - OPO

1 stop20h 30mUnited Airlines

mar. 3/1012:35 pmOPO - STL

2 stops25h 46mUnited Airlines

Deal found 1/8

$436

dom. 2/222:19 pmSTL - OPO

2 stops20h 21mBritish Airways

mar. 3/108:20 amOPO - STL

2 stops20h 28mBritish Airways

Deal found 1/8

$443

sáb. 3/77:00 pmSTL - OPO

2 stops32h 30mUnited Airlines

jue. 3/1912:35 pmOPO - STL

2 stops25h 46mUnited Airlines

Deal found 1/8

$506

sáb. 2/76:00 amSTL - OPO

2 stops19h 40mAmerican Airlines

sáb. 2/148:20 amOPO - STL

2 stops15h 40mAmerican Airlines

Deal found 1/8

$511

sáb. 4/117:40 pmSTL - OPO

2 stops42h 20mIberia

mar. 4/218:40 pmOPO - STL

2 stops31h 34mIberia

Deal found 1/7

$565

jue. 1/2211:22 amSTL - OPO

2 stops18h 18mUnited Airlines

lun. 1/2612:30 pmOPO - STL

2 stops32h 00mUnited Airlines

Deal found 1/7

$577

sáb. 3/77:00 pmSTL - OPO

2 stops45h 25mMultiple Airlines

jue. 3/196:00 amOPO - STL

2 stops38h 29mMultiple Airlines

Deal found 1/6

$607

sáb. 4/117:40 pmSTL - OPO

2 stops18h 55mBritish Airways

mar. 4/218:40 pmOPO - STL

1 stop28h 50mBritish Airways

Deal found 1/7

$617

lun. 8/3112:10 pmSTL - OPO

1 stop12h 40mUnited Airlines

sáb. 9/129:00 amOPO - STL

2 stops17h 59mUnited Airlines

Deal found 1/8

$758

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 enero 8, 2026.

dom. 2/227:00 amSTL - OPO

1 stop20h 30mUnited Airlines

mar. 3/1012:35 pmOPO - STL

1 stop16h 16mUnited Airlines

Deal found 1/8

$436

dom. 2/222:19 pmSTL - OPO

2 stops20h 21mBritish Airways

mar. 3/108:20 amOPO - STL

2 stops20h 28mBritish Airways

Deal found 1/8

$443

sáb. 2/76:00 amSTL - OPO

2 stops19h 40mAmerican Airlines

sáb. 2/148:20 amOPO - STL

2 stops15h 40mAmerican Airlines

Deal found 1/8

$511

sáb. 4/117:40 pmSTL - OPO

2 stops42h 20mIberia

mar. 4/218:40 pmOPO - STL

2 stops31h 34mIberia

Deal found 1/7

$565

lun. 5/255:00 pmSTL - OPO

1 stop11h 30mDelta

jue. 6/45:00 amOPO - STL

2 stops21h 31mDelta

Deal found 1/8

$792

sáb. 3/77:00 pmSTL - OPO

2 stops38h 15mLufthansa

jue. 3/1912:35 pmOPO - STL

1 stop16h 16mLufthansa

Deal found 1/6

$798

lun. 5/255:00 pmSTL - OPO

1 stop11h 30mMultiple Airlines

jue. 6/412:25 pmOPO - STL

1 stop34h 15mMultiple Airlines

Deal found 1/7

$807

sáb. 3/77:00 pmSTL - OPO

2 stops32h 30mUnited Airlines

jue. 3/1912:35 pmOPO - STL

2 stops25h 46mUnited Airlines

Deal found 1/8

$506

sáb. 4/117:40 pmSTL - OPO

2 stops18h 55mBritish Airways

mar. 4/218:40 pmOPO - STL

1 stop28h 50mBritish Airways

Deal found 1/7

$617

jue. 1/2211:22 amSTL - OPO

2 stops18h 18mUnited Airlines

lun. 1/2612:30 pmOPO - STL

2 stops32h 00mUnited Airlines

Deal found 1/7

$577

Last-minute flights from St. Louis to Porto
Discover last-minute flight deals from St. Louis to Porto. Data last updated enero 8, 2026 and is based on user searches.

jue. 1/2211:22 amSTL - OPO

2 stops18h 18mUnited Airlines

lun. 1/2612:30 pmOPO - STL

2 stops32h 00mUnited Airlines

Deal found 1/7

$577

sáb. 2/76:00 amSTL - OPO

2 stops19h 40mAmerican Airlines

sáb. 2/148:20 amOPO - STL

2 stops15h 40mAmerican Airlines

Deal found 1/8

$511

sáb. 2/73:11 pmSTL - OPO

2 stops17h 54mUnited Airlines

sáb. 2/146:00 amOPO - STL

3 stops22h 14mUnited Airlines

Deal found 1/8

$6,863

dom. 2/227:00 amSTL - OPO

1 stop20h 30mUnited Airlines

mar. 3/1012:35 pmOPO - STL

1 stop16h 16mUnited Airlines

Deal found 1/8

$436

dom. 2/222:19 pmSTL - OPO

2 stops20h 21mBritish Airways

mar. 3/108:20 amOPO - STL

2 stops20h 28mBritish Airways

Deal found 1/8

$443

dom. 2/224:05 pmSTL - OPO

2 stops17h 10mMultiple Airlines

mar. 3/1011:15 amOPO - STL

3 stops32h 40mMultiple Airlines

Deal found 1/8

$1,077

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

dom. 2/22

7:00 am-9:30 am

1 stop20h 30m

Porto

mar. 3/10

12:35 pm-11:51 pm

1 stop16h 16m

$436

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

dom. 2/22

2:19 pm-4:40 pm

2 stops20h 21m

Porto

mar. 3/10

8:20 am-11:48 pm

2 stops20h 28m

$443

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

sáb. 3/7

7:00 pm-9:30 am

2 stops32h 30m

Porto

jue. 3/19

12:35 pm-9:21 am

2 stops25h 46m

$506

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

sáb. 2/7

6:00 am-7:40 am

2 stops19h 40m

Porto

sáb. 2/14

8:20 am-6:00 pm

2 stops15h 40m

$511

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

sáb. 4/11

7:40 pm-8:00 pm

2 stops42h 20m

Porto

mar. 4/21

8:40 pm-10:14 pm

2 stops31h 34m

$565

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

jue. 1/22

11:22 am-11:40 am

2 stops18h 18m

Porto

lun. 1/26

12:30 pm-2:30 pm

2 stops32h 00m

$577

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

sáb. 4/11

7:40 pm-8:35 pm

2 stops18h 55m

Porto

mar. 4/21

8:40 pm-7:30 pm

1 stop28h 50m

$617

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

lun. 5/25

5:00 pm-10:30 am

1 stop11h 30m

Porto

jue. 6/4

5:00 am-8:31 pm

2 stops21h 31m

$792

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

sáb. 3/7

7:00 pm-3:15 pm

2 stops38h 15m

Porto

jue. 3/19

12:35 pm-11:51 pm

1 stop16h 16m

$798

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

lun. 5/25

5:00 pm-10:30 am

1 stop11h 30m

Porto

jue. 6/4

12:25 pm-4:40 pm

1 stop34h 15m

$807

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/8

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 January.

Provider	Price Accuracy	Trust Score*
FlightHub	Price Accuracy3 stars	Trust Score*1 star
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Ovago	Price Accuracy2 stars	Trust Score*2 stars
AranGrant	Price Accuracy2 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.

Reviews of airlines servicing Porto

Read reviews from past customers who have flown Delta, United Airlines, and Air Canada 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.

Delta

7.9

Good

8,032 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.

Delta

7.9

Good

8,032 reviews

Delta

7.9

Good

8,032 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

United Airlines

7.4

Good

9,142 reviews

Delta

7.9

Good

8,032 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

Air Canada

7.1

Good

10,603 reviews

Delta

7.9

Good

8,032 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

Lufthansa

6.8

Okay

7,698 reviews

Delta

7.9

Good

8,032 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

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 18h 18m. Fly via Iberia, United Airlines, or British Airways 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 $520, was found to be the cheapest airline from St. Louis to Porto.Alternate airlines to your destination round-trip include Delta and United Airlines. Users have found that Lufthansa is 50% 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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Vila Nova de Gaia

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Other flights to Porto

Top 4 airlines flying from St. Louis to Porto

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest$520	Average$1,207	FlexibilityNo cancel fee	On-time76%
Delta	Cheapest$713	Average$963	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$760	Average$1,114	FlexibilityNo cancel fee	On-time69%
Air Canada	Cheapest$787	Average$969	FlexibilityNo cancel fee	On-time67%

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$436+ 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 2/22. 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

One-way 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 enero 8, 2026.

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 enero 8, 2026.

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 January.

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.

Reviews of airlines servicing Porto

Get insights into the airlines that provide service to Porto. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Porto. Reviews last updated enero 8, 2026.

Read reviews from past customers who have flown Delta, United Airlines, and Air Canada 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?

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Alternative routes for St. Louis to Porto

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Top 4 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 enero 8, 2026.