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$808+ Cheap flights from Porto (OPO) to St. Louis (STL)

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 10/29. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — STL
Nov 11 — Nov 181
Tue 11/11
Tue 11/18
1 adult, Economy
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Find flight deals from Porto to St. Louis

Cheapest flights from Porto to St. Louis
Explore the most affordable flight options available from Porto to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 12, 2025.

This Expedia deal was found by Cheapflights users on 10/11. 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 10/2711:15 amOPO - STL
2 stops28h 11mKLM
Fri 10/316:14 pmSTL - OPO
2 stops35h 16mKLM
Deal found 10/11$1,080
This Gotogate deal was found by Cheapflights users on 10/11. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/274:10 pmOPO - STL
2 stops36h 34mLufthansa
Fri 10/3111:49 amSTL - OPO
1 stop16h 41mLufthansa
Deal found 10/11$1,101
This United Airlines deal was found by Cheapflights users on 10/11. 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.
Mon 10/2712:35 pmOPO - STL
1 stop33h 00mUnited Airlines
Fri 10/3111:49 amSTL - OPO
1 stop16h 41mUnited Airlines
Deal found 10/11$1,380
This Mytrip deal was found by Cheapflights users on 10/11. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/274:10 pmOPO - STL
3 stops29h 25mMultiple Airlines
Fri 10/316:30 amSTL - OPO
2 stops19h 35mMultiple Airlines
Deal found 10/11$1,557

Cheap flight deals from Porto to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Porto (OPO) to St. Louis (STL). 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 October 12, 2025.

Round-trip from

$850
(Delta)

One-way from

$838
(Thrive Travel)
From Porto to Lambert-St Louis
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One-way flight from Porto to Lambert-St Louis
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Porto to St. Louis 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 October 12, 2025.
Use the filters below to find and compare flights from Porto to St. Louis that are best for you.

Fly from

Porto

Fly to

St. Louis

Route

Depart

Return

Price

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Fri 2/6

6:30 am-9:44 am

2 stops33h 14m

Lambert-St Louis

Sun 2/8

10:45 am-10:30 am

2 stops17h 45m

$850

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Mon 10/27

11:15 am-10:26 am

2 stops28h 11m

Lambert-St Louis

Fri 10/31

6:14 pm-10:30 am

2 stops35h 16m

$1,080

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Mon 10/27

4:10 pm-11:44 pm

2 stops36h 34m

Lambert-St Louis

Fri 10/31

11:49 am-9:30 am

1 stop16h 41m

$1,101

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Mon 10/27

12:35 pm-4:35 pm

1 stop33h 00m

Lambert-St Louis

Fri 10/31

11:49 am-9:30 am

1 stop16h 41m

$1,380

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Mon 10/27

4:10 pm-4:35 pm

3 stops29h 25m

Lambert-St Louis

Fri 10/31

6:30 am-7:05 am

2 stops19h 35m

$1,557

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 10/29

7:20 pm-7:16 pm

2 stops28h 56m

$808

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Wed 10/29

6:00 am-2:55 pm

1 stop13h 55m

$1,058

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/10

Best time to book a flight from Porto to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Porto 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.

Related info for your journey

Find useful and relevant information for your journey from Porto to St. Louis. 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 Porto to St. Louis?

    Airlines like Delta, KLM, and Lufthansa fly from Porto to St. Louis in about 28h 11m. The time it takes to get you to your destination can typically vary by up to 8h 23m. There are 4154 mi between Porto and St. Louis. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • Can I find deals for flights from Porto to St. Louis that include hotel bookings?

    Yes. In addition to deals on Porto to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Porto to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Porto to St. Louis.

  • Can I find deals for business class flights from Porto to St. Louis?

    Yes. Cheapflights offers flight deals from Porto to St. Louis 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

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