Find flights
Deals
Insights
When to book
FAQs & Tips
Airlines

STL - OPO

$544 Find cheap flights from St. Louis to Porto

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Porto departing on 7/22. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
0 bags
Sat 6/29
Sat 7/6

Search hundreds of travel sites at once for deals on flights to Porto

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Porto, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Porto, as well as popular online travel agencies
In the last 7 days travelers have searched 42,686,544 times on KAYAK, and here is why:

Save 21% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Bundle and saveSave money when you bundle your flight + hotel.

Cheap flight deals from St. Louis to Porto (STL-OPO)

 
These are the cheapest deals for flights from St. Louis to Porto currently on KAYAK along with options from the most popular airlines KAYAK users selected for this route. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.

Recent round-trip flight deals from St. Louis to Porto

Recommended round-trip deals departing in the coming months from the most popular airlines that fly from St. Louis to Porto.

Recent one-way flight deals from St. Louis to Porto

Only flying one-way? Below are some of the best one-way flight deals from St. Louis to Porto found on KAYAK recently.

Recent last minute flight deals from St. Louis to Porto

Leaving soon but still want a bargain? Check out these latest deals for last minute flights from St. Louis to Porto.

Recent direct flight deals from St. Louis to Porto

The latest deals for direct flights from St. Louis to Porto so you can sit back and relax without the need for a layover.

Cheap bus & train deals from St. Louis to Porto

Find recent round-trip train or bus tickets from St. Louis to Porto.

All round-trip flight deals to Porto

The cheapest plane tickets to Porto found on KAYAK recently.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
6:22 pm - 7:35 amSTL-OPO
31h 13m3 stops
8:15 am - 9:00 amOPO-STL
30h 45m2 stops
$929American Airlines
Find Deal
Mon, Sep 9 - Sat, Sep 21
6:51 pm - 7:35 amSTL-OPO
30h 44m2 stops
8:15 am - 9:00 amOPO-STL
30h 45m2 stops
$931American Airlines
Find Deal
Mon, Sep 9 - Sat, Sep 21
4:05 pm - 6:30 pmSTL-OPO
20h 25m2 stops
8:40 am - 8:00 pmOPO-STL
17h 20m2 stops
$934Air Canada
Find Deal
Sat, Sep 7 - Fri, Sep 20
4:05 pm - 11:30 amSTL-OPO
37h 25m2 stops
8:40 am - 8:00 pmOPO-STL
17h 20m2 stops
Mon, Sep 9 - Fri, Sep 20
5:32 pm - 9:45 amSTL-OPO
10h 13m1 stop
6:00 am - 1:30 pmOPO-STL
13h 30m1 stop
$947United Airlines
Find Deal
Sat, Sep 7 - Fri, Sep 20
5:32 pm - 9:45 amSTL-OPO
10h 13m1 stop
6:00 am - 7:47 pmOPO-STL
19h 47m2 stops
$957United Airlines
Find Deal
Sat, Sep 7 - Fri, Sep 20
5:30 pm - 9:45 amSTL-OPO
10h 15m1 stop
8:40 am - 8:00 pmOPO-STL
17h 20m2 stops
Wed, Oct 2 - Fri, Oct 11
12:10 pm - 7:35 amSTL-OPO
37h 25m2 stops
12:25 pm - 8:15 pmOPO-STL
37h 50m2 stops
$965Iberia
Find Deal
Thu, Oct 3 - Wed, Oct 9
10:45 am - 7:35 amSTL-OPO
14h 50m2 stops
12:20 pm - 8:07 pmOPO-STL
37h 47m2 stops
$968Iberia
Find Deal
Fri, Oct 11 - Mon, Oct 21
4:05 pm - 6:30 pmSTL-OPO
20h 25m2 stops
6:15 am - 8:00 pmOPO-STL
19h 45m2 stops
$1,028Air Canada
Find Deal
Sat, Sep 7 - Sat, Sep 21
10:19 am - 6:55 amSTL-OPO
14h 36m2 stops
$544United Airlines
Find Deal
Mon, Jul 22
5:05 pm - 3:30 pmSTL-OPO
16h 25m2 stops
$546Air France
Find Deal
Sat, Sep 28
3:25 pm - 10:45 pmSTL-OPO
25h 20m1 stop
$867Lufthansa
Find Deal
Wed, Jul 24
6:09 pm - 9:15 pmSTL-OPO
21h 06m3 stops
Wed, Jul 24

Flights from St. Louis to Porto - Travel Insights & Trends

Get data-powered insights and trends into flights from St. Louis to Porto to help you find the cheapest flights, the best time to fly and much more.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights from St. Louis to Porto, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.
The cheapest month for flights from St. Louis to Porto is February, where tickets cost $631 on average. On the other hand, the most expensive months are June and May, where the average cost of tickets is $1,619 and $1,493 respectively.

Which airlines provide the cheapest flights from St. Louis to Porto?

The cheapest price for the route for each airline clicked by KAYAK users in the last 72 hours.
In the last 72 hours, the cheapest one-way ticket from St. Louis to Porto found on KAYAK was with United Airlines for $544. American Airlines proposed a round-trip connection from $929 and Air Canada from $934.

Good to know

Low season

November

High season

June

Cheapest flight

$544
Best time to beat the crowds with an average 23% drop in price.
Most popular time to fly with an average 47% increase in price.
Flight from St. Louis to Porto

When to book flights from St. Louis to Porto

Are your dates flexible? Find out the best times to travel from St. Louis to Porto based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from St. Louis to Porto

  • What is the cheapest flight from St. Louis to Porto?

    In the last 3 days, the lowest price for a flight from St. Louis to Porto was $544 for a one-way ticket and $929 for a round-trip.

  • Do I need a passport to fly between St. Louis and Porto?

    Yes, you’ll need a passport to travel to Porto from St. Louis.

  • Which airports will I be using when flying from St. Louis to Porto?

    St. Louis and Porto are both served by 1 main airport. You will leave St. Louis from Lambert-St Louis and will be arriving at Porto.

  • Which aircraft models fly most regularly from St. Louis to Porto?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from St. Louis to Porto?

    Star Alliance, SkyTeam, and oneworld are the airline alliances operating flights between St. Louis and Porto, with SkyTeam being the most commonly used for this route.

  • Which is the best airline for flights from St. Louis to Porto, United Airlines or Iberia?

    The two airlines most popular with KAYAK users for flights from St. Louis to Porto are United Airlines and Iberia. With an average price for the route of $1,231 and an overall rating of 7.4, United Airlines is the most popular choice. Iberia is also a great choice for the route, with an average price of $1,001 and an overall rating of 7.1.

  • How does KAYAK find such low prices on flights from St. Louis to Porto?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Porto.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Porto?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Porto from St. Louis is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Porto?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Porto with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and OPO can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Porto?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Porto from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Top airlines flying from St. Louis to Porto

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Porto. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Porto? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 10777 reviews
7.2Comfort
7.7Boarding
6.7Food
8.1Crew
7.1Entertainment
Airline reviews

Well....let's start from the point that I had to stay in airport for 12 hours instead of 2 that was scheduled. Poor company and even worst customer service. Never again....

2.0 MediocreAnonymous, May 2024MIA - FRA
Read more about United Airlines reviews

Well....let's start from the point that I had to stay in airport for 12 hours instead of 2 that was scheduled. Poor company and even worst customer service. Never again....

The flight and boarding were easy peasy. I was traveling with my 4-year-old, so a smooth boarding experience was especially appreciated. My only piece of feedback is really about where our gate was in O'Hare. They've shoved four gates into a tiny corner of the B terminal and there isn't early enough room or seating for everyone. Not United's problem, but did dent the overall experience.

We liked the fully reclinable seats. Had center seats, so it was difficult to talk to spouse. Crew was great

Aisle chair was good and liked the foot bar preventing you from putting your foot in the isle, The breakfast on this international flight to Zurich was horrible (Europeans, specially, used to good food) may make this a dealbreaker for booking with United Airlines again. I agreed with my Spanish fellow passenger.

Dinner was okay but the breakfast was not eatable on the flight San Francisco to Zurich.

There was no screens on board AND the WiFi didn’t work. My seat was broken and couldn’t recline so I couldn’t even sleep. The flight attendants didn’t offer anything to make it more comfortable. It was such an old cramped plane, when the person in front of me reclined I couldn’t even open my tray table. All the United ads talk about guaranteeing everyone gets a screen!

The Wi-Fi was unavailable on this flight for some reason.

The flight was delayed almost 2 hours. Bad customer service etc. I will never fly Luthansa. Ever!!!

On time take off…US cabins look tired and need of refresh!

Fine. Though no food or entertainment so the survey needs to be updated with those options.

Ability to select seating would be nice. We were family of three and they had us seated back to back and one of us on the other side of the plane??? That is pretty goofy. Especially when tickets were placed two months in advance.

We had a seat that would not function. No Wifi or inflight entertainment was available. Food was very poor. Attendants were very accommodating and apologized for the problems.

My son and I are 193 cm tall. We had reserved and paid for seats with extra leg room towards the front of the cabin. The day of the flight, we learned that Iberia had changed aircraft. We were assigned regular seats way back in the cabin. When we landed from our first leg we spoke with agents at the gate and we were told that they couldn’t improve our seats because the flight was full.

Our flight was delayed by 2-hrs but I understand it was beyond the scope of the crew members

I am quite satisfied. The flight was on time and landed early. Staff was friendly.

Overall was good except for the seat which, for an 8 hour intercontinental flight, was uncorfortable. For that kind of flight seats should have more space, even for economy seats.

Other than a late takeoff (not British Airways fault) and some delays with baggage, it was a terrific flight. The crew in business class was superb and the seat and accommodations clean and modern. Could not have asked for more.

Needed more info on connecting flight. Late flight made very short connection. Lost luggage that we still do not have!

Seats comfortable on economy plus and attendants very helpful. Food was ok. Bathrooms needed servicing.

Original flight was cancelled - After waiting 2 hours for new take-off times. Then had to stand in line for 3 hours, ending at 2:30 am - to be told, " No hotel rooms anywhere in Dallas". No way for me to get any rest at DFW at that time of night.

Book cheap flights from St. Louis to Porto

Recent one-way flight deals

 
Only flying one-way? Below are some of the best one-way flight deals from St. Louis to Porto found on KAYAK in the last 72 hours.
7/22Mon
2 stopsUnited Airlines
14h 36mSTL-OPO
$544
9/28Sat
2 stopsAir France
16h 25mSTL-OPO
$546
7/24Wed
1 stopLufthansa
25h 20mSTL-OPO
$867
7/24Wed
3 stops
21h 06mSTL-OPO
$984

Search by stops

Search by airline

Search by price

St. Louis - Porto Flights

Departure:

St. Louis (STL)United States

Destination:

Porto (OPO)Portugal

Return flight deals:

Porto - St. Louis

Cabin classes:

Browse destinations: