$784+ 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 9/29. Fares are subject to change and may not be available on all flights or dates of travel.
STL — OPO
May 4 — May 111
1 adult, Economy
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Find cheap flights from St. Louis to Porto with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”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
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.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 April 29, 2025.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 2 stars |
Round-trip from | $1,314 (Air France) |
One-way from | $918 (United Airlines) |
Popular in | June |
Cheapest in | November |
Average price | $1,245 |
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 29, 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 29, 2025.
This Expedia deal was found by Cheapflights users on 4/29. 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.
Mon 9/291:30 pmSTL - OPO
1 stop14h 05mAir Canada
Thu 10/96:00 amOPO - STL
2 stops19h 57mAir Canada
Deal found 4/29![Air Canada logo]()
$784
This Justfly.com deal was found by Cheapflights users on 4/29. 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.
Mon 9/291:30 pmSTL - OPO
1 stop14h 05mMultiple Airlines
Thu 10/912:10 pmOPO - STL
1 stop31h 20mMultiple Airlines
Deal found 4/29![Multiple Airlines logo]()
$816
This United Airlines deal was found by Cheapflights users on 4/29. 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 Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/274:40 pmSTL - OPO
2 stops58h 55mUnited Airlines
Sun 10/126:00 amOPO - STL
2 stops43h 33mUnited Airlines
Deal found 4/29![United Airlines logo]()
$867
This FlightHub deal was found by Cheapflights users on 4/29. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/61:29 pmSTL - OPO
2 stops37h 21mScandinavian Airlines
Fri 8/155:55 pmOPO - STL
2 stops35h 44mScandinavian Airlines
Deal found 4/29![Scandinavian Airlines logo]()
$899
This Gurufare deal was found by Cheapflights users on 4/29. 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 Gurufare is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/275:30 pmSTL - OPO
2 stops34h 50mLufthansa
Sat 10/116:15 amOPO - STL
2 stops39h 23mLufthansa
Deal found 4/29![Lufthansa logo]()
$905
This oojo deal was found by Cheapflights users on 4/29. 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.
Wed 5/73:43 pmSTL - OPO
2 stops36h 02mTurkish Airlines
Wed 5/1410:50 amOPO - STL
2 stops33h 57mTurkish Airlines
Deal found 4/29![Turkish Airlines logo]()
$1,792
Cheapflights Fare Finder
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 April 29, 2025.
Use the filters below to find and compare flights from St. Louis to Porto that are best for you.
Fly from
St. Louis
Fly to
Porto
Route
Depart
Return
Price
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Thu 5/15
7:06 pm-3:30 pm
2 stops14h 24m
Porto
Fri 5/30
6:40 am-8:49 pm
2 stops20h 09m
$1,314
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Sat 5/17
7:30 am-6:30 pm
2 stops29h 00m
Porto
Sat 5/31
6:00 am-7:58 pm
2 stops19h 58m
$1,315
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Thu 5/15
8:30 am-11:15 am
2 stops20h 45m
Porto
Fri 5/30
12:35 pm-9:25 pm
1 stop14h 50m
$1,747
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Wed 5/7
3:43 pm-9:45 am
2 stops36h 02m
Porto
Wed 5/14
10:50 am-2:47 pm
2 stops33h 57m
$1,792
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Wed 5/7
3:30 pm-11:20 am
1 stop13h 50m
Porto
Wed 5/14
6:00 am-3:47 pm
2 stops15h 47m
$1,835
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Sat 6/14
1:30 pm-9:35 am
1 stop14h 05m
$918
St. LouisPorto
STL - OPO
STLOPO
Lambert-St Louis
Sat 6/14
9:50 am-9:35 am
2 stops17h 45m
$923
- 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 $1,071). 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 April 29, 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 April 29, 2025.
Food
6.6
Boarding
7.7
Overall
7.4
Comfort
7.3
Crew
8.1
Entertainment
7.1
Reviews
1 / 20
4.0
OkayThomas,Mar 2025
SFO - TPE
Food
6.6
Boarding
7.7
Overall
7.4
Comfort
7.3
Crew
8.1
Entertainment
7.1
Reviews
1 / 20
4.0
OkayThomas,Mar 2025
SFO - TPE
Food
6.6
Boarding
7.7
Overall
7.4
Comfort
7.3
Crew
8.1
Entertainment
7.1
Reviews
1 / 20
4.0
OkayThomas,Mar 2025
SFO - TPE
Food
6.6
Boarding
7.7
Overall
7.4
Comfort
7.3
Crew
8.1
Entertainment
7.1
Reviews
1 / 20
4.0
OkayThomas,Mar 2025
SFO - TPE
Food
6.6
Boarding
7.7
Overall
7.4
Comfort
7.3
Crew
8.1
Entertainment
7.1
Reviews
1 / 20
4.0
OkayThomas,Mar 2025
SFO - TPE
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.
Traveling to a place near St. Louis?
Book flights to St. Louis if you plan to visit one of these locationsAveiro
Coimbra
Matosinhos
Arcos de Valdevez
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 3 airlines flying from St. Louis to Porto
Discover the top 3 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 April 29, 2025.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$612 | Average$1,250 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$711 | Average$1,132 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$713 | Average$963 | FlexibilityNo cancel fee | On-timeN/A |