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

Delta, at $822, was found to be the cheapest airline from St. Louis to Porto.Alternate airlines to your destination round-trip include United Airlines and Air Canada. Users have found that Delta is 19% cheaper than the other options available to this destination.

What are the cheapest airlines to fly from St. Louis to Porto one-way?

For one-way options, check prices for American Airlines. According to our data, you can fly for as low as $681. Users have also found prices from $863 and $890 on United Airlines and Lufthansa, respectively.

What is the cheapest day to fly from St. Louis to Porto?

Travelers seeking maximum savings on their St. Louis to Porto flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Monday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

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 Delta, Lufthansa or United Airlines as they are the most popular for this route.

What is the cheapest day to fly round-trip from St. Louis to Porto?

Users have found that leaving on a Wednesday can be a cost-effective option. It’s possible to save up to 94% on your flight compared to booking on days when demand is much higher.

What is the cheapest month to fly from St. Louis to Porto?

Flights from St. Louis to Porto lean towards being more expensive in June. Prices are generally better when you fly from St. Louis to Porto in November, with the cheapest ticket starting at $557.

Most accurate provider : When it comes to deals on St. Louis-Porto flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Porto flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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.

$681+ Flights from St. Louis to Porto

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Cheap flight deals from St. Louis to Porto

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 2 stars
Round-trip from	$810 (Air Canada)
One-way from	$681 (American Airlines)
Popular in	June
Cheapest in	November
Average price	$1,245

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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Highest demand for flights based on searches. 27% potential increase in price ($389 potential increase over avg. RT price).

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Cheapest flight prices on average. 4% potential price decrease ($42 potential savings vs. average RT price).

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Average for round-trip flights in April 2025

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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 April 17, 2025.

Wed 5/72:30 pmSTL - OPO

2 stops22h 00mMultiple Airlines

Wed 5/146:00 amOPO - STL

2 stops19h 58mMultiple Airlines

Deal found 4/16

$810

Sat 5/105:17 pmSTL - OPO

2 stops35h 23mDelta

Fri 5/236:40 amOPO - STL

2 stops22h 58mDelta

Deal found 4/16

$822

Wed 9/179:17 amSTL - OPO

2 stops18h 08mUnited Airlines

Sun 9/2111:20 amOPO - STL

1 stop14h 37mUnited Airlines

Deal found 4/16

$852

Wed 9/179:17 amSTL - OPO

2 stops18h 08mAir Canada

Sun 9/2111:20 amOPO - STL

2 stops14h 13mAir Canada

Deal found 4/16

$858

Fri 9/1911:38 amSTL - OPO

2 stops18h 02mAmerican Airlines

Sat 9/278:15 amOPO - STL

2 stops16h 53mAmerican Airlines

Deal found 4/16

$937

Wed 5/73:30 pmSTL - OPO

1 stop18h 15mLufthansa

Wed 5/146:00 amOPO - STL

2 stops15h 47mLufthansa

Deal found 4/16

$1,200

Tue 4/229:52 amSTL - OPO

2 stops39h 43mIberia

Wed 5/74:55 pmOPO - STL

2 stops31h 38mIberia

Deal found 4/15

$3,319

Thu 4/243:29 pmSTL - OPO

2 stops22h 51mBritish Airways

Fri 5/99:10 pmOPO - STL

2 stops32h 41mBritish Airways

Deal found 4/15

$5,733

Tue 4/227:25 amSTL - OPO

2 stops44h 10mAustrian Airlines

Tue 5/62:05 pmOPO - STL

2 stops39h 44mAustrian Airlines

Deal found 4/15

$7,066

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 April 17, 2025.

Wed 5/72:30 pmSTL - OPO

2 stops22h 00mMultiple Airlines

Wed 5/146:00 amOPO - STL

2 stops19h 58mMultiple Airlines

Deal found 4/16

$810

Sat 5/105:17 pmSTL - OPO

2 stops35h 23mDelta

Fri 5/236:40 amOPO - STL

2 stops22h 58mDelta

Deal found 4/16

$822

Wed 9/179:17 amSTL - OPO

2 stops18h 08mUnited Airlines

Sun 9/2111:20 amOPO - STL

1 stop14h 37mUnited Airlines

Deal found 4/16

$852

Wed 9/179:17 amSTL - OPO

2 stops18h 08mAir Canada

Sun 9/2111:20 amOPO - STL

2 stops14h 13mAir Canada

Deal found 4/16

$858

Fri 9/1911:38 amSTL - OPO

2 stops18h 02mAmerican Airlines

Sat 9/278:15 amOPO - STL

2 stops16h 53mAmerican Airlines

Deal found 4/16

$937

Wed 5/73:30 pmSTL - OPO

1 stop18h 15mLufthansa

Wed 5/146:00 amOPO - STL

2 stops15h 47mLufthansa

Deal found 4/16

$1,200

Last-minute flights from St. Louis to Porto
Discover last-minute flight deals from St. Louis to Porto. Data last updated April 17, 2025 and is based on user searches.

Tue 4/229:52 amSTL - OPO

2 stops39h 43mIberia

Wed 5/74:55 pmOPO - STL

2 stops31h 38mIberia

Deal found 4/15

$3,319

Tue 4/227:25 amSTL - OPO

2 stops44h 10mAustrian Airlines

Tue 5/62:05 pmOPO - STL

2 stops39h 44mAustrian Airlines

Deal found 4/15

$7,066

Wed 4/233:30 pmSTL - OPO

2 stops19h 55mAir Canada

Tue 5/68:40 amOPO - STL

2 stops17h 03mAir Canada

Deal found 4/15

$7,031

Wed 4/233:30 pmSTL - OPO

1 stop13h 50mLufthansa

Tue 5/64:35 pmOPO - STL

1 stop26h 55mLufthansa

Deal found 4/15

$7,088

Thu 4/243:29 pmSTL - OPO

2 stops22h 51mBritish Airways

Fri 5/99:10 pmOPO - STL

2 stops32h 41mBritish Airways

Deal found 4/15

$5,733

Sat 4/265:33 pmSTL - OPO

2 stops34h 22mMultiple Airlines

Sun 5/44:05 pmOPO - STL

2 stops29h 42mMultiple Airlines

Deal found 4/16

$1,653

Sat 4/264:25 pmSTL - OPO

1 stop11h 20mUnited Airlines

Sun 5/46:00 amOPO - STL

2 stops15h 47mUnited Airlines

Deal found 4/16

$1,972

Wed 5/73:30 pmSTL - OPO

1 stop18h 15mLufthansa

Wed 5/146:00 amOPO - STL

2 stops15h 47mLufthansa

Deal found 4/16

$1,200

Sun 5/111:30 pmSTL - OPO

2 stops39h 55mMultiple Airlines

Sat 5/2412:05 pmOPO - STL

1 stop31h 25mMultiple Airlines

Deal found 4/16

$1,065

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 April 17, 2025.

Thu 9/2511:38 amSTL - OPO

2 stops18h 02mAmerican Airlines

Deal found 4/16

$681

Thu 9/255:21 pmSTL - OPO

1 stop10h 24mUnited Airlines

Deal found 4/16

$863

Sat 6/145:27 pmSTL - OPO

2 stops35h 48mLufthansa

Deal found 4/16

$890

Sat 6/141:30 pmSTL - OPO

1 stop14h 05mAir Canada

Deal found 4/16

$918

Cheapflights Fare Finder

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

Wed 5/7

2:30 pm-6:30 pm

2 stops22h 00m

Porto

Wed 5/14

6:00 am-7:58 pm

2 stops19h 58m

$810

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 5/10

5:17 pm-10:40 am

2 stops35h 23m

Porto

Fri 5/23

6:40 am-11:38 pm

2 stops22h 58m

$822

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 9/17

9:17 am-9:25 am

2 stops18h 08m

Porto

Sun 9/21

11:20 am-7:57 pm

1 stop14h 37m

$852

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 9/17

9:17 am-9:25 am

2 stops18h 08m

Porto

Sun 9/21

11:20 am-7:33 pm

2 stops14h 13m

$858

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 9/19

11:38 am-11:40 am

2 stops18h 02m

Porto

Sat 9/27

8:15 am-7:08 pm

2 stops16h 53m

$937

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 5/7

3:30 pm-3:45 pm

1 stop18h 15m

Porto

Wed 5/14

6:00 am-3:47 pm

2 stops15h 47m

$1,200

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 6/14

1:00 pm-6:55 am

2 stops35h 55m

$879

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/17

Most accurate provider: When it comes to deals on St. Louis-Porto flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Porto flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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 month to book a flight from St. Louis to Porto?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Porto (average of $523). Flying from St. Louis to Porto in June is currently the most expensive (average of $1,081). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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

Unlike in the afternoon, when flights are generally more expensive, you can save up to 36% on flights from St. Louis to Porto by exploring options for tickets at noon.

Rainfall in Porto by month

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.

Temperature in Porto by month

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).

Reviews of airlines servicing Porto

Read through reviews of airlines operating flights from St. Louis to Porto, such as Delta, United Airlines and American Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,916 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Delta

8.0

Very good

7,916 reviews

Delta

8.0

Very good

7,916 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

United Airlines

7.4

Good

8,667 reviews

Delta

8.0

Very good

7,916 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

American Airlines

7.2

Good

10,000 reviews

Delta

8.0

Very good

7,916 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Air Canada

7.0

Good

9,143 reviews

Delta

8.0

Very good

7,916 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Lufthansa

6.7

Okay

7,012 reviews

Delta

8.0

Very good

7,916 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Related info for your journey

What are the cheapest airlines flying from St. Louis to Porto round-trip?
Delta, at $822, was found to be the cheapest airline from St. Louis to Porto.Alternate airlines to your destination round-trip include United Airlines and Air Canada. Users have found that Delta is 19% cheaper than the other options available to this destination.
What are the cheapest airlines to fly from St. Louis to Porto one-way?
For one-way options, check prices for American Airlines. According to our data, you can fly for as low as $681. Users have also found prices from $863 and $890 on United Airlines and Lufthansa, respectively.
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.
What is the cheapest month to book a flight from St. Louis to Porto?
Currently, January is the cheapest month in which you can book a flight from St. Louis to Porto (average of $523). Flying from St. Louis to Porto in June is currently the most expensive (average of $1,081). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Aveiro

Coimbra

Matosinhos

Arcos de Valdevez

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Other flights to Porto

Top 3 airlines flying from St. Louis to Porto

Airline	Cheapest	Average	Flexibility	On-time
Lufthansa	Cheapest$612	Average$1,277	FlexibilityNo cancel fee	On-time76%
United Airlines	Cheapest$711	Average$1,093	FlexibilityNo cancel fee	On-time69%
Delta	Cheapest$713	Average$963	FlexibilityNo cancel fee	On-timeN/A

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$681+ Cheap flights from St. Louis (STL) to Porto (OPO)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/25. 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

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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 April 17, 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 April 17, 2025.

Cheapflights Fare Finder

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

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 month to book a flight from St. Louis to Porto?

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

Find hourly flight availability from St. Louis to Porto. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 17, 2025.

Rainfall in Porto by month

Plan your trip to Porto by taking into account the average rainfall totals by month.

Temperature in Porto by month

Plan your trip to Porto by taking into account the average temperature totals by month.

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 April 17, 2025.

Read through reviews of airlines operating flights from St. Louis to Porto, such as Delta, United Airlines and American Airlines. Reviews also offer insight into each airline's 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.

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

What are the cheapest airlines to fly from St. Louis to Porto one-way?

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?

What is the cheapest month to book a flight from St. Louis to Porto?

Traveling to a place near St. Louis?

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Alternative routes for St. Louis to Porto

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Top 3 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 April 17, 2025.