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$406+ 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 4/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — OPO
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
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Cheap flight deals from St. Louis to Porto

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Porto (OPO). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$585
(Expedia)

One-way from

$406
(Kiwi.com)

Popular in

June

Cheapest in

November

Average price

$706
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. 28% potential increase in price ($402 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($51 potential savings vs. average RT price).
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Average for round-trip flights in February 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 February 20, 2025.

This Expedia deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/253:50 pmSTL - OPO
2 stops16h 00mMultiple Airlines
Mon 3/314:35 pmOPO - STL
2 stops52h 14mMultiple Airlines
Deal found 2/20$585
This United deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/163:50 pmSTL - OPO
2 stops38h 45mUnited Airlines
Mon 3/2412:25 pmOPO - STL
2 stops30h 58mUnited Airlines
Deal found 2/19$641
This Delta deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/115:35 pmSTL - OPO
2 stops16h 00mDelta
Sun 4/205:00 amOPO - STL
2 stops17h 52mDelta
Deal found 2/20$1,038
This KAYAK deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/45:18 pmSTL - OPO
2 stops40h 22mLufthansa
Sat 10/114:35 pmOPO - STL
1 stop26h 55mLufthansa
Deal found 2/19$1,098
This American Airlines deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/411:38 amSTL - OPO
2 stops18h 02mAmerican Airlines
Sat 10/118:15 amOPO - STL
2 stops16h 52mAmerican Airlines
Deal found 2/19$1,168
This Iberia deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/26:29 pmSTL - OPO
2 stops19h 26mIberia
Wed 4/98:15 amOPO - STL
2 stops21h 18mIberia
Deal found 2/19$3,759
This oojo deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/228:00 amSTL - OPO
2 stops25h 50mTurkish Airlines
Mon 9/294:50 pmOPO - STL
2 stops27h 28mTurkish Airlines
Deal found 2/19$3,802
This Justfly.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/214:05 pmSTL - OPO
2 stops17h 15mAir Canada
Tue 9/308:40 amOPO - STL
2 stops16h 53mAir Canada
Deal found 2/19$5,181
This Air France deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/235:45 pmSTL - OPO
2 stops15h 45mAir France
Sun 9/286:35 amOPO - STL
2 stops16h 10mAir France
Deal found 2/19$9,035

Find flights from St. Louis to Porto within your budget

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, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.

Fly from

St. Louis

Fly to

Porto

Route

Depart

Return

Price

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 3/25

3:50 pm-12:50 pm

2 stops16h 00m

Porto

Mon 3/31

4:35 pm-2:49 pm

2 stops52h 14m

$585

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 3/16

3:50 pm-11:35 am

2 stops38h 45m

Porto

Mon 3/24

12:25 pm-2:23 pm

2 stops30h 58m

$641

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 4/11

5:35 pm-3:35 pm

2 stops16h 00m

Porto

Sun 4/20

5:00 am-4:52 pm

2 stops17h 52m

$1,038

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 4/2

6:29 pm-7:55 pm

2 stops19h 26m

Porto

Wed 4/9

8:15 am-11:33 pm

2 stops21h 18m

$3,759

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 4/2

3:30 pm-11:20 am

1 stop13h 50m

Porto

Tue 4/8

4:35 pm-1:30 pm

1 stop26h 55m

$5,799

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 4/9

4:57 pm-9:50 am

3 stops58h 53m

$406

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/20

  • 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.

Travel insights for flights from St. Louis to Porto

Get recent, data-driven insights about flights from St. Louis to Porto including ideal travel times, pricing trends, and more.

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 $1,092). 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?

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 February 20, 2025.

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

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

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

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 February 20, 2025.
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Comfort

8.0

Overall

8.0

Crew

8.5

Entertainment

7.9

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
8,219 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Comfort

8.0

Overall

8.0

Crew

8.5

Entertainment

7.9

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
8,765 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Comfort

8.0

Overall

8.0

Crew

8.5

Entertainment

7.9

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.

Iberia
7.0
Good
2,639 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Comfort

8.0

Overall

8.0

Crew

8.5

Entertainment

7.9

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
6,986 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Comfort

8.0

Overall

8.0

Crew

8.5

Entertainment

7.9

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

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?

    United Airlines, at $641, was found to be the cheapest airline from St. Louis to Porto.Alternate airlines to your destination round-trip include Delta and Iberia. Users have found that United Airlines is 36% 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.

  • 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 $1,092). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Aveiro
Coimbra
Matosinhos
Arcos de Valdevez

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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.
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Top 2 airlines flying from St. Louis to Porto

Discover the top 2 airlines that operate flights from St. Louis to Porto. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$752Average$1,222FlexibilityNo cancel feeOn-time69%
DeltaCheapest$753Average$963FlexibilityNo cancel feeOn-timeN/A
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