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 Lufthansa or Delta 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.

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.

$490+ Flights from St. Louis to Porto

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Cheap 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 December 12, 2025.

Thu 12/2510:04 amSTL - OPO

2 stops18h 26mKLM

Thu 1/16:35 amOPO - STL

2 stops20h 06mKLM

Deal found 12/10

$1,682

Thu 12/259:08 amSTL - OPO

2 stops26h 07mBritish Airways

Sat 1/37:50 pmOPO - STL

2 stops29h 32mBritish Airways

Deal found 12/10

$2,109

Mon 12/224:05 pmSTL - OPO

2 stops21h 10mMultiple Airlines

Mon 1/57:35 amOPO - STL

3 stops33h 21mMultiple Airlines

Deal found 12/10

$2,407

Thu 12/254:05 pmSTL - OPO

3 stops20h 55mMultiple Airlines

Thu 1/110:20 amOPO - STL

3 stops35h 09mMultiple Airlines

Deal found 12/10

$2,424

Mon 12/226:35 pmSTL - OPO

2 stops36h 15mLufthansa

Mon 1/54:10 pmOPO - STL

2 stops37h 49mLufthansa

Deal found 12/10

$2,479

Thu 12/254:05 pmSTL - OPO

2 stops23h 15mMultiple Airlines

Sat 1/311:35 amOPO - STL

3 stops29h 21mMultiple Airlines

Deal found 12/10

$2,891

Thu 12/256:35 pmSTL - OPO

2 stops47h 05mLufthansa

Sat 1/34:15 pmOPO - STL

1 stop27h 40mLufthansa

Deal found 12/10

$3,152

Mon 12/228:05 amSTL - OPO

3 stops22h 45mAir Canada

Mon 1/58:30 amOPO - STL

3 stops19h 13mAir Canada

Deal found 12/10

$3,604

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 December 12, 2025.

Sat 1/2411:22 amSTL - OPO

2 stops18h 18mLufthansa

Sat 1/316:00 amOPO - STL

2 stops23h 59mLufthansa

Deal found 12/10

$490

Sat 1/247:25 amSTL - OPO

2 stops21h 05mDelta

Mon 2/25:00 amOPO - STL

2 stops21h 06mDelta

Deal found 12/10

$492

Sat 1/2410:19 amSTL - OPO

2 stops18h 11mKLM

Sat 1/319:25 amOPO - STL

2 stops17h 18mKLM

Deal found 12/10

$492

Fri 1/233:50 pmSTL - OPO

1 stop13h 50mLufthansa

Sat 1/316:00 amOPO - STL

2 stops23h 59mLufthansa

Deal found 12/10

$491

Sun 1/256:57 pmSTL - OPO

2 stops33h 33mDelta

Sun 2/15:00 amOPO - STL

2 stops21h 43mDelta

Deal found 12/10

$492

Fri 1/236:25 amSTL - OPO

2 stops22h 05mDelta

Tue 2/311:15 amOPO - STL

2 stops35h 27mDelta

Deal found 12/10

$492

Thu 1/226:25 amSTL - OPO

2 stops22h 00mDelta

Tue 2/35:00 amOPO - STL

2 stops21h 43mDelta

Deal found 12/10

$492

Wed 1/219:45 amSTL - OPO

2 stops18h 45mDelta

Sat 1/315:00 amOPO - STL

2 stops21h 43mDelta

Deal found 12/10

$492

Mon 1/2610:19 amSTL - OPO

2 stops18h 11mDelta

Tue 2/35:00 amOPO - STL

2 stops17h 37mDelta

Deal found 12/10

$492

Tue 1/271:00 pmSTL - OPO

2 stops15h 30mDelta

Tue 2/35:00 amOPO - STL

2 stops17h 37mDelta

Deal found 12/10

$492

Wed 1/216:25 amSTL - OPO

2 stops22h 05mDelta

Thu 1/295:00 amOPO - STL

2 stops21h 43mDelta

Deal found 12/10

$492

Thu 1/229:45 amSTL - OPO

2 stops18h 40mDelta

Sun 2/15:00 amOPO - STL

2 stops21h 43mDelta

Deal found 12/10

$492

Last-minute flights from St. Louis to Porto
Discover last-minute flight deals from St. Louis to Porto. Data last updated December 12, 2025 and is based on user searches.

Fri 1/169:57 amSTL - OPO

2 stops19h 43mUnited Airlines

Tue 1/206:00 amOPO - STL

2 stops22h 58mUnited Airlines

Deal found 12/9

$605

Wed 1/216:25 amSTL - OPO

2 stops22h 05mDelta

Mon 2/25:00 amOPO - STL

2 stops21h 43mDelta

Deal found 12/10

$492

Wed 1/213:50 pmSTL - OPO

1 stop13h 50mLufthansa

Tue 2/36:00 amOPO - STL

2 stops19h 27mLufthansa

Deal found 12/10

$501

Wed 1/2111:22 amSTL - OPO

2 stops19h 53mLufthansa

Thu 1/294:15 pmOPO - STL

1 stop27h 40mLufthansa

Deal found 12/10

$504

Fri 1/233:50 pmSTL - OPO

1 stop13h 50mLufthansa

Sat 1/316:00 amOPO - STL

2 stops23h 59mLufthansa

Deal found 12/10

$491

Fri 1/233:50 pmSTL - OPO

1 stop13h 50mLufthansa

Fri 1/301:45 pmOPO - STL

2 stops33h 58mLufthansa

Deal found 12/10

$513

Sat 1/2411:22 amSTL - OPO

2 stops18h 18mLufthansa

Sat 1/316:00 amOPO - STL

2 stops23h 59mLufthansa

Deal found 12/10

$490

Sat 1/2411:22 amSTL - OPO

2 stops19h 28mLufthansa

Fri 1/301:45 pmOPO - STL

2 stops40h 14mLufthansa

Deal found 12/10

$505

Sat 1/244:05 pmSTL - OPO

2 stops20h 05mMultiple Airlines

Sat 1/318:50 amOPO - STL

1 stop12h 39mMultiple Airlines

Deal found 12/10

$1,117

Sun 1/2511:23 amSTL - OPO

2 stops17h 07mMultiple Airlines

Fri 1/305:00 amOPO - STL

2 stops21h 37mMultiple Airlines

Deal found 12/10

$1,161

Sun 1/254:05 pmSTL - OPO

2 stops37h 10mAir Canada

Thu 1/296:00 amOPO - STL

2 stops39h 29mAir Canada

Deal found 12/10

$1,162

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 December 12, 2025.

Tue 6/22:18 pmSTL - OPO

3 stops36h 42mMultiple Airlines

Deal found 12/11

$568

Tue 6/210:00 pmSTL - OPO

1 stop15h 30mBritish Airways

Deal found 12/11

$647

Find flight deals from St. Louis to Porto

Most accurate provider	eDreams 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$490 (FlightHub)
Popular in	July
Cheapest in	February

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. 19% potential increase in price ($258 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($35 potential savings vs. average RT price).

Search Deals

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 1/24

11:22 am-11:40 am

2 stops18h 18m

Porto

Sat 1/31

6:00 am-11:59 pm

2 stops23h 59m

$490

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 1/23

3:50 pm-11:40 am

1 stop13h 50m

Porto

Sat 1/31

6:00 am-11:59 pm

2 stops23h 59m

$491

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 1/24

7:25 am-10:30 am

2 stops21h 05m

Porto

Mon 2/2

5:00 am-8:06 pm

2 stops21h 06m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 1/24

10:19 am-10:30 am

2 stops18h 11m

Porto

Sat 1/31

9:25 am-8:43 pm

2 stops17h 18m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 1/25

6:57 pm-10:30 am

2 stops33h 33m

Porto

Sun 2/1

5:00 am-8:43 pm

2 stops21h 43m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 1/23

6:25 am-10:30 am

2 stops22h 05m

Porto

Tue 2/3

11:15 am-4:42 pm

2 stops35h 27m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Thu 1/22

6:25 am-10:25 am

2 stops22h 00m

Porto

Tue 2/3

5:00 am-8:43 pm

2 stops21h 43m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 1/21

9:45 am-10:30 am

2 stops18h 45m

Porto

Sat 1/31

5:00 am-8:43 pm

2 stops21h 43m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 1/26

10:19 am-10:30 am

2 stops18h 11m

Porto

Tue 2/3

5:00 am-4:37 pm

2 stops17h 37m

$492

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 1/27

1:00 pm-10:30 am

2 stops15h 30m

Porto

Tue 2/3

5:00 am-4:37 pm

2 stops17h 37m

$492

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

Showing 1-10 of 14 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 December.

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

*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 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

8,009 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

8,009 reviews

Delta

7.9

Good

8,009 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

United Airlines

7.4

Good

9,095 reviews

Delta

7.9

Good

8,009 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

Air Canada

7.1

Good

10,514 reviews

Delta

7.9

Good

8,009 reviews

Reviews

1 / 20

6.0

Good

Jim,Nov 2025

AVL - ATL

Lufthansa

6.8

Okay

7,626 reviews

Delta

7.9

Good

8,009 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 Lufthansa or Delta 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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Other flights to Porto

Top 4 airlines flying from St. Louis to Porto

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest$520	Average$1,214	FlexibilityNo cancel fee	On-time76%
Delta	Cheapest$713	Average$963	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$760	Average$1,133	FlexibilityNo cancel fee	On-time69%
Air Canada	Cheapest$787	Average$1,005	FlexibilityNo cancel fee	On-time67%

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$490+ 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 1/24. 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

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 December 12, 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 December 12, 2025.

Find flight deals from St. Louis to Porto

Most accurate provider

Most trusted provider

Round-trip from

Popular in

Cheapest in

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 December.

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 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?

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 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 December 12, 2025.