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655 € Cheap Flights from St Louis to Porto

Compare St Louis to Porto flight deals

Find the cheapest month or even day of the year to fly to Porto

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Flight deals from St Louis to Porto

Looking for a cheap last-minute deal or the best return flight from St Louis Airport to Porto Airport? If you want to travel next month, return fares start from 714 €. Find the lowest prices on one-way and return tickets right here.
Porto.655 € per passenger.Departing Wed, 21 Apr, returning Wed, 5 May.Return flight with Delta.Outbound indirect flight with Delta, departs from St Louis on Wed, 21 Apr, arriving in Porto.Inbound indirect flight with Delta, departs from Porto on Wed, 5 May, arriving in St Louis.Price includes taxes and charges.From 655 €, select.
Porto.702 € per passenger.Departing Mon, 12 Apr, returning Mon, 26 Apr.Return flight with Delta.Outbound indirect flight with Delta, departs from St Louis on Mon, 12 Apr, arriving in Porto.Inbound indirect flight with Delta, departs from Porto on Mon, 26 Apr, arriving in St Louis.Price includes taxes and charges.From 702 €, select.
Porto.714 € per passenger.Departing Mon, 10 Aug, returning Tue, 25 Aug.Return flight with Frontier Airlines and Ryanair.Outbound indirect flight with Frontier Airlines, departs from St Louis on Mon, 10 Aug, arriving in Porto.Inbound indirect flight with Ryanair, departs from Porto on Tue, 25 Aug, arriving in St Louis.Price includes taxes and charges.From 714 €, select.
Porto.746 € per passenger.Departing Tue, 6 Oct, returning Fri, 16 Oct.Return flight with Delta.Outbound indirect flight with Delta, departs from St Louis on Tue, 6 Oct, arriving in Porto.Inbound indirect flight with Delta, departs from Porto on Fri, 16 Oct, arriving in St Louis.Price includes taxes and charges.From 746 €, select.
Porto.784 € per passenger.Departing Fri, 18 Sep, returning Sat, 26 Sep.Return flight with Frontier Airlines and Ryanair.Outbound indirect flight with Frontier Airlines, departs from St Louis on Fri, 18 Sep, arriving in Porto.Inbound indirect flight with Ryanair, departs from Porto on Sat, 26 Sep, arriving in St Louis.Price includes taxes and charges.From 784 €, select.
Porto.829 € per passenger.Departing Mon, 28 Sep, returning Fri, 2 Oct.Return flight with Brussels Airlines and Transavia France.Outbound indirect flight with Brussels Airlines, departs from St Louis on Mon, 28 Sep, arriving in Porto.Inbound indirect flight with Transavia France, departs from Porto on Fri, 2 Oct, arriving in St Louis.Price includes taxes and charges.From 829 €, select.
Porto.866 € per passenger.Departing Tue, 28 Jul, returning Wed, 5 Aug.Return flight with Frontier Airlines and Ryanair.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 28 Jul, arriving in Porto.Inbound indirect flight with Ryanair, departs from Porto on Wed, 5 Aug, arriving in St Louis.Price includes taxes and charges.From 866 €, select.
Porto.877 € per passenger.Departing Tue, 25 Aug, returning Mon, 7 Sep.Return flight with Delta.Outbound indirect flight with Delta, departs from St Louis on Tue, 25 Aug, arriving in Porto.Inbound indirect flight with Delta, departs from Porto on Mon, 7 Sep, arriving in St Louis.Price includes taxes and charges.From 877 €, select.
Porto.915 € per passenger.Departing Wed, 23 Dec, returning Sun, 27 Dec.Return flight with Delta.Outbound indirect flight with Delta, departs from St Louis on Wed, 23 Dec, arriving in Porto.Inbound indirect flight with Delta, departs from Porto on Sun, 27 Dec, arriving in St Louis.Price includes taxes and charges.From 915 €, select.
Porto.932 € per passenger.Departing Sat, 18 Jul, returning Fri, 24 Jul.Return flight with Frontier Airlines and Air Transat.Outbound indirect flight with Frontier Airlines, departs from St Louis on Sat, 18 Jul, arriving in Porto.Inbound indirect flight with Air Transat, departs from Porto on Fri, 24 Jul, arriving in St Louis.Price includes taxes and charges.From 932 €, select.

Find the cheapest month to fly from St Louis to Porto

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like St Louis to Porto flights are currently cheapest in April.
Jul
from 932 €
Aug
from 714 €
Sep
from 784 €
Oct
from 746 €
Nov
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Dec
from 915 €
Jan
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Feb
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Mar
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Apr
from 702 €
May
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Jun
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St Louis to Porto: Alternative routes

Compare routes from St Louis to Porto below. You may find an airport to fly into that's cheaper, faster, or easier than Porto.

Porto

12km from central Porto
ClosestCheapest
from 655 €
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Vila Real

76km from central Porto
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Viseu G. Lobato

81km from central Porto
Search flights

St Louis to Porto: Flight information

The things to know before you go.
Cheapest flight found655 €
Cheapest month to flyApril

Finding cheap flights from St Louis to Porto: Frequently asked questions

The best price we found for a return flight from St Louis to Porto is 655 €. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
Currently, there are no airlines that fly direct from St Louis to Porto. But we found flights with one or more stops from 655 €.
As of July 2026, there are no flights flying from St Louis to Porto.
The cheapest month to fly from St Louis to Porto is usually April.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from St Louis Airport to Porto Airport on Wednesday, 21 April 2027.
No airlines currently offer direct flights between St Louis Airport and Porto Airport. Most routes have one or more stops.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Porto but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Porto is around 40 days in advance, so don’t leave your flight to the last minute.

Currently, Delta offers the cheapest flight tickets to Porto.

Flying from St Louis Airport (STL) to Porto Airport (OPO): what you need to know

  • Porto's timezone is UTC+0, which makes Porto six hours ahead of St Louis.

  • Leave enough time to make your STL to OPO flight. As a general rule, turn up at least two hours before international departures and an hour ahead for domestic flights.

  • Be prepared for longer queues in popular months such as July. Arriving up to four hours in advance for international flights and two hours for domestic departures will help ensure a smooth travel experience.

  • Think about adding a stopover when booking your ticket from St Louis Airport to Porto Airport. Simply uncheck 'Direct flights only' to break up your trip, or visit a new city along the way. Here are some options between STL and OPO:

    • New York Newark Airport

    • Toronto Pearson International Airport

    • Montreal Pierre Elliott Trudeau Airport

How to find the cheapest flights from St Louis Airport (STL) to Porto Airport (OPO)

  • At the moment, 320 € is the lowest price we've found for a one-way St Louis Airport to Porto Airport flight. The best price for a return plane ticket is 655 €. Remember that fares could change due to demand when booking.

  • Don't wait until the last minute. You're more likely to find cheap tickets from STL to OPO if you book in advance. Airlines often have some excellent early bird deals.

  • If you're willing to be flexible with your travel plans, try using the 'Whole month' search tool. It'll show you the lowest price across each month when searching for your flight from St Louis Airport to Porto Airport.

  • There's no need to check every day to see if fares have gone down when you create a Price Alert. We'll notify you as soon as there's a change in price on cheap flights from STL to OPO.

  • Find the ideal flight for you by using the filters. To see the 'Best,' 'Fastest' or 'Cheapest' flights from St Louis Airport to Porto Airport, use the 'Sort by' function. You can also filter results by departure and arrival times, airline, and journey duration.

Handy information about St Louis Airport (STL)

Arriving at Porto Airport (OPO)

  • Book a hotel near OPO if you're catching a late St Louis Airport to Porto Airport flight. Settle into one of these accommodation options and skip the long transfer:

  • Travel at your own speed with a Porto Airport rental car. Pick up your wheels from Klass Wagen, Goldcar or Drive & Go and experience more of Porto and beyond.

  • Booking your ride from Porto Airport about three weeks in advance gives you the best chance of locking in a great deal.

Getting from Porto Airport (OPO) to central Porto

  • Porto Airport to the centre of Porto has a drive time of about 20 minutes. It's approximately 11 kilometres away.

  • It takes roughly 30 minutes if you're travelling by public transport.

When to fly to Porto Airport (OPO)

  • The quietest month for a flight from St Louis Airport to Porto Airport is March, while August is the most popular. Choose the ideal time to go to Porto based on whether you prefer a bustling atmosphere or a more laid-back vibe.

  • The warmest month in Porto is August, with the temperature ranging between 14ºC (57ºF) and 32ºC (90ºF). Book your flights from St Louis Airport to Porto Airport in this month if this is the type of weather you enjoy.

  • January sees average temperatures of between 3ºC (37ºF) and 14ºC (57ºF). Look for cheap tickets from STL to OPO sometime around then if you want to travel in cooler conditions.

Explore more of Portugal

  • You've visited Porto, now it's time to explore other parts of Portugal. Journey around 274 kilometres south to Lisbon to tick off its top sights. From Pasteis de Belém to belém and Real Mosteiro de Santa Maria de Belém, you'll have a packed itinerary ahead.

  • Amadora is another essential stop in Portugal and is around 274 kilometres south of Porto. No trip is complete without experiencing Roman Villa, Park Fantasia and Palácio dos Condes da Lousã.

Plan the rest of your trip from St Louis to Porto

Prices shown on this page are estimated lowest prices only. Found in the last 12 days.