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STL - OPO

$529 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 7/24. 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
Tue 6/4
Tue 6/11

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 42,830,901 times on KAYAK, and here is why:

Save 22% or moreCompare multiple travel sites with one search.

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

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Porto that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
12:00 pm - 11:30 amSTL-OPO
17h 30m2 stops
11:10 am - 3:21 pmOPO-STL
34h 11m2 stops
$1,025
Find Deal
Tue, Jul 2 - Thu, Jul 11
4:18 pm - 7:55 pmSTL-OPO
21h 37m2 stops
8:35 pm - 5:14 pmOPO-STL
26h 39m2 stops
$1,027Iberia
Find Deal
Tue, Sep 3 - Sat, Sep 14
11:05 am - 7:35 amSTL-OPO
14h 30m2 stops
12:20 pm - 8:54 amOPO-STL
26h 34m2 stops
$1,092American Airlines
Find Deal
Thu, Jun 13 - Wed, Jun 19
5:25 pm - 9:45 amSTL-OPO
10h 20m1 stop
9:00 am - 3:58 pmOPO-STL
12h 58m1 stop
$1,118United Airlines
Find Deal
Thu, Jun 13 - Wed, Jun 19
5:25 pm - 9:45 amSTL-OPO
10h 20m1 stop
9:00 am - 10:15 pmOPO-STL
19h 15m2 stops
$1,122United Airlines
Find Deal
Thu, Jun 13 - Wed, Jun 19
10:34 am - 6:55 pmSTL-OPO
26h 21m3 stops
6:20 pm - 5:28 pmOPO-STL
29h 08m3 stops
$1,136
Find Deal
Tue, Sep 3 - Sat, Sep 14
6:08 am - 9:45 amSTL-OPO
21h 37m1 stop
12:10 pm - 3:21 pmOPO-STL
33h 11m2 stops
$1,274
Find Deal
Tue, Jul 2 - Thu, Jul 11
5:18 pm - 10:25 amSTL-OPO
35h 07m2 stops
4:45 pm - 1:30 pmOPO-STL
26h 45m1 stop
$1,314Lufthansa
Find Deal
Tue, Sep 3 - Sat, Sep 14
7:37 am - 11:40 amSTL-OPO
22h 03m2 stops
8:15 am - 5:17 pmOPO-STL
15h 02m2 stops
$1,780American Airlines
Find Deal
Tue, Oct 8 - Wed, Oct 23
1:10 pm - 10:25 amSTL-OPO
15h 15m2 stops
6:00 am - 1:30 pmOPO-STL
13h 30m1 stop
$1,887Lufthansa
Find Deal
Tue, Oct 8 - Wed, Oct 23

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 $529. Iberia proposed a round-trip connection from $1,027 and American Airlines from $1,092.

Good to know

Low season

November

High season

June

Cheapest flight

$529
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 $529 for a one-way ticket and $1,025 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, and oneworld are the airline alliances operating flights between St. Louis and Porto, with oneworld 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 11118 reviews
7.7Boarding
7.2Comfort
8.1Crew
6.7Food
7.1Entertainment
Airline reviews

Should have video screens Plane audio was poor and without wired connection hard to understand crew. Should serve more than just cups of water and pretzels on six hour flight. Did not see crew rest of flight. Fix charging sockets to retain charging blocks.

2.0 MediocreTed, May 2024IAD - SFO
Read more about United Airlines reviews

Should have video screens Plane audio was poor and without wired connection hard to understand crew. Should serve more than just cups of water and pretzels on six hour flight. Did not see crew rest of flight. Fix charging sockets to retain charging blocks.

I paid $380 for my one-way ticket from California to Minnesota. The fair did not include online check-in. I received instructions from their app to check in at a kiosk. At the kiosk, the boarding pass would not print until an actual person came to verify that I had a personal item and not a carry-on item, On the plane, the person next to me was drunk and allowed to continue to order alcohol. United is garbage I’d rather fly spirit.

The plane was dirty and the in seat air wasn't blowing as planes usually do.

Generally good but there wasn’t any staff available when my luggage didn’t appear at baggage claim in Fresno. It took about half an hour to locate a staff member to open up the locked room where it was being kept.

Do not like the feeling of being in the basic economy. Everyone should feel good no matter what.

All flights were on time and boarding was issue free

Terrible! The plane was old and you are required to connect your own device to their Wi-Fi rather than have entertainment options in the back of the seat in front of you. The Wi-Fi went out during the flight and there was only one plug for the devices every two seats. Three out of five surrounding my family did not work. The seats and spaces under them were so small I could not fit my backpack, which I’ve always brought on flights and fit before no problem. The crew were unpleasant and patronizing.

Great! The plane was decently sized and comfortable. The staff was nice and there was great in flight entertainment

Food was terrible Not many options Stewards dont care Delay

Water service would be great. The way they board is terrible. Slow passengers first😂😂 They need to smart up a bit

I liked the friendly crew and desk staff, all very helpful. I was surprised and a little annoyed on my outbound flight from LGW to MCO as I had prepaid and booked my seat, which was all correct at check in on my boarding pass. when I got on the plane someone was in my seat ! I was moved to another seat. The food choice is quite limited and I feel that an option of a muffin for breakfast snack would be welcomed, not everyone wants egg or bacon wrap. The choice of entertainment is good, plenty to keep you busy on a long haul flight. I liked the option offered to have the cabin bag checked into the hold, it saved me as an older, lone traveller lifting my case into the overhead locker or finding there was no space.

good service from crew. Before the would have an option between cookies or nuts as snacks.. Now, there are only cookies. too bad. People who can not have sugar don't have a choice.

Iberia personnel on the ground is so rude. I would think twice in the future before booking another Iberia flight

I’m hoping for WiFi included. Everything else was very good

All corners have been cut and it’s a cheap experience that no longer is distinguished from most other cheap airlines

An average flight experience. For our transatlantic portion, they provided a main meal and two snacks. However, the food was not very tasty and the drinks far too small and infrequent for such a long flight. The regrettable part of the flight was that the toilets were extremely filthy. I feel this is unacceptable.

Rude security cunts. However the lady that issued my boarding ticket when I was flying back from New York was lovely & helpful!!

Appalling! The flight was delayed by 3.5 hours and the American Airlines staff at the airport where nit very helpful. Once boarded, the flight crew were unhelpful, the food was poor and the aircraft was tatty.

I called prior to flying to confirm our baggage allowance which was 5 bags. On our outbound flight thee were no problems. On the return flight we were charged for each bag totaling $400! We are working with customer service to resolve the issue.

Late boarding. Delayed departure leading to rushed connection at Madrid Barajas. Not necessarily Iberia's fault but delay loading cargo didn't help.

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.
7/24Wed
2 stopsUnited Airlines
16h 50mSTL-OPO
$529
7/24Wed
3 stops
24h 15mSTL-OPO
$698
7/24Wed
1 stopLufthansa
13h 55mSTL-OPO
$878

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St. Louis - Porto Flights

Departure:

St. Louis (STL)United States

Destination:

Porto (OPO)Portugal

Return flight deals:

Porto - St. Louis

Cabin classes:

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