$347 Find Cheap Flights from St. Louis to Portugal

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 Portugal departing on 10/19. 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
1 adult, Economy, 0 bags

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Cheap Flights from St. Louis to Portugal

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Lisbon
Lisbon1 stop$759
Porto
Porto1 stop$735
Lajes
Lajes2 stops$2,221
Lisbon
Lisbon1 stop$759
Porto
Porto1 stop$735
Lajes
Lajes2 stops$2,221

Book Cheap St. Louis to Portugal Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Portugal 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 for you by selecting your travel dates on KAYAK.

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

Tue, Nov 17 - Fri, Nov 20
United Airlines Logo
11:45 am - 9:30 am
STL
-
OPO
15h 45m
1 stop
United Airlines Logo
6:00 am - 1:55 pm
OPO
-
STL
13h 55m
1 stop
$735United Airlines
Tue, Nov 17 - Fri, Nov 20
United Airlines Logo
11:45 am - 9:30 am
STL
-
OPO
15h 45m
1 stop
United Airlines Logo
6:00 am - 1:55 pm
OPO
-
STL
13h 55m
1 stop
$736United Airlines
Tue, Nov 17 - Fri, Nov 20
United Airlines Logo
10:23 am - 9:30 am
STL
-
OPO
17h 07m
2 stops
United Airlines Logo
6:00 am - 1:55 pm
OPO
-
STL
13h 55m
1 stop
$740United Airlines
Tue, Nov 17 - Fri, Nov 20
United Airlines Logo
1:27 pm - 9:30 am
STL
-
OPO
14h 03m
2 stops
United Airlines Logo
12:30 pm - 12:34 am
OPO
-
STL
18h 04m
2 stops
$750United Airlines
Wed, Nov 4 - Wed, Nov 11
Multiple Airlines Logo
4:15 pm - 11:00 am
STL
-
LIS
12h 45m
1 stop
Multiple Airlines Logo
5:00 am - 1:55 pm
LIS
-
STL
14h 55m
1 stop
$759Multiple Airlines
Mon, Oct 26 - Wed, Nov 4
Multiple Airlines Logo
4:15 pm - 11:00 am
STL
-
LIS
13h 45m
1 stop
Multiple Airlines Logo
5:00 am - 1:55 pm
LIS
-
STL
14h 55m
1 stop
$760Multiple Airlines
Wed, Nov 4 - Tue, Nov 10
Scandinavian Airlines Logo
3:42 pm - 4:05 pm
STL
-
LIS
18h 23m
2 stops
Scandinavian Airlines Logo
4:55 pm - 11:39 pm
LIS
-
STL
36h 44m
2 stops
$771Scandinavian Airlines
Wed, Nov 4 - Tue, Nov 10
Scandinavian Airlines Logo
3:42 pm - 4:05 pm
STL
-
LIS
18h 23m
2 stops
Scandinavian Airlines Logo
4:55 pm - 11:39 pm
LIS
-
STL
36h 44m
2 stops
$772Scandinavian Airlines
Mon, Oct 26 - Wed, Nov 4
Air Canada Logo
9:23 am - 9:50 am
STL
-
LIS
19h 27m
2 stops
Air Canada Logo
11:20 am - 2:18 pm
LIS
-
STL
32h 58m
2 stops
$784Air Canada
Wed, Nov 4 - Wed, Nov 11
Air Canada Logo
6:40 am - 11:00 am
STL
-
LIS
22h 20m
2 stops
Air Canada Logo
11:20 am - 2:18 pm
LIS
-
STL
32h 58m
2 stops
$789Air Canada
Booking Insights

KAYAK's insights & trends for St. Louis to Portugal flights

Get data-powered insights and trends into flights from St. Louis to Portugal 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 Portugal?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Portugal, 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 Portugal is March, when tickets cost $458 (return) on average. On the other hand, the most expensive months are June and July, when the average cost of round-trip tickets is $791 and $754 respectively.

How far in advance should I book a flight from St. Louis to Portugal?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Portugal, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from St. Louis to Portugal, you should book around 1 week before departure. For the absolute cheapest price, our data suggests you should book 1 week before departure.

Good to know

Low seasonFebruary
Cheapest flight$347
Best time to beat the crowds with an average 45% drop in price.
Most popular time to fly with an average 21% increase in price.
Flight from St. Louis to Porto

FAQs - booking Portugal flights

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

    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 Portugal.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from St. Louis to Portugal 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 Portugal?

    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 from St. Louis to Portugal with an airline and back with another airline.

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

    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 from St. Louis to Portugal up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines serving from St. Louis to Portugal

 
Need help choosing which airline to fly with from St. Louis to Portugal? 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.
7.9
DeltaOverall score based on 8450 reviews
7.8Entertainment
7.8Comfort
8.1Boarding
7.2Food
8.5Crew
Airline reviews

I continue to be satisfied with Delta’s excellent service out of LGA. The digit id works well and gets me through security in no time. Whenever possible, I choose Delta.

10.0 Excellentangela, May 2026
LGA - PBI
Read more Delta reviews

I continue to be satisfied with Delta’s excellent service out of LGA. The digit id works well and gets me through security in no time. Whenever possible, I choose Delta.

Was revoked with Jet Blue due to delay from Kenya Air

The Boarding process was great. Particularly since my wife and I require assistance. The flight attendants were amazing. We travel frequently; they honestly were a cut above. 😀

Enjoyed it very much. Especially liked the free WiFi that Delta offers.

Smooth flight. Left on time, and got in 15 minutes early. Onboard video was great

For some reason, TSA Atlanta didn’t have my bag on the flight on time and they don’t have to provide Delta a reason for that.

WiFi didn’t work on two of four planes. Flight attendants were not overly friendly or welcoming. Planes were extremely slow to board and deplane.

Delta does a great job with entertainment and free wifi. I can still be in touch with my colleagues while in the air.

Aside from a completely packed plane, I really have no complaints.

Bus to plane was delayed for no apparent reason and our luggage was still on the belt when they shut it off. Took about 20 minutes to turn it back on to get our luggage.

As I wrote earlier, poor planning and/or communication. At least twice, we were told that we would be boarding in less than ten minutes, only to have the flight again delayed at least another hour.

This flight is a quick way to get to Chicago, but a bit expensive.

Very comfortable seating and the Flight staff were very attentive. The premium economy section that I was seated in was very clean, updated, and well appointed. I would highly recommend flying United Airlines as this experience was better than the Japan Airlines business class that I flew several months ago.

Our flight was canceled same day and we were never informed. Had to pay more and worse seating on another airline.

Our flight to Rome, Italy was cancelled the day of and we were never informed. We only found out because I was trying to get into my husbands account and called to get his account number. Had to pay more for worse seating on another airline.

My service dog and I were asked to deplane just before they closed the door - clearly very last minute they couldn’t find the documentation that I have filled out many many times before that is for flying service animals. I purposely purchase 3seats (a whole row) since he is large and not all passengers want to sit next to a dog on a cross country flight. The plane departed with my husband on it!!! They made me fill out a hard copy of the same form and had to reschedule me on a later flight where they could find 3 seats together!! I’ve done this so many times before - clearly the error was on their part in a technology glitch - but really people - do better!! Very traumatic - and my husband had to wait for us when he landed ….so bad. Poor pup was confused and tired.

First class ticket gets you no seat back entertainment? I have to bring my own laptop to see a movie? And most of their movies have ADS? No thank you. Worse: Tiny snacks only on a 2 hr flight?

Late- that’s what United does best. Missed my connection, rebooked to a flight 17 hours later and had to spend $500 on a hotel. What did I get? A $15 meal voucher. What can you get in an airport for $15. I hate United so much.

OK, I don’t expect much from coach class. Everything basically is pretty lousy. But at least I expect my bloody luggage to get from A to B. Tap Airlines lost my luggage and it has been more than 24 hours in Lisbon and they still have not located my luggage. On top of that, they are incredibly unhelpful. They feel actually dismissive. This lousy customer service.

Late plane. Only one crew on the ground so we b had to wait for Denver flight to come in, board, and depart. At 78 yrs of age I was not pleased trying to get my connection. What really made me angry was the notification you sent me to hurry up or I would miss my connection. Why tell me to hurry up when you got me in late. It was not a good way of treating customers.

Requested early boarding to disinfect seat, tray table, etc. before general boarding. Instructed to board after wheelchair passengers. Waited on jet bridge behind 12 wheelchair passengers. Stopped immediately after entering plane to wait for gate agent in rear of plane cleaning a seat that was wet, got to my row and found both seats adjacent to mine already occupied, with the lack of room making it impossible for me to clean my own space and defeating the purpose of my boarding early. Cleaned the armrests and tray table as best I could.

Seat bottom cushions are not good. I’m 165# & they hurt my butt. Plenty of legroom.

The wifi experience is awful. I had to try again and again, taking over 30 minutes, to connect to the wifi. I had to watch the same two ads over and over until I was finally successful. Once connected, it was anything but "high speed" and disconnected at least three times during the flight.

Fine. Nothing to write home about. The plane left on time, and arrived on time.

I was downgraded from first class to coach due to an airplane change. They pulled me out of line and I was the very last person to board the plane stuck in the middle seat with no overhead place to put my carry-.on. Very poor customer service.

Seat comfort was poor (no lumbar or lower back support).

The airplane seats were spacious and comfortable, and the flight attendants were friendly and attentive. The food was delicious like never before. The blankets and toiletries were thoughtfully provided. The captain's navigation was steady and reliable. In short, having flown with Starlux, I won't consider any other airline next time.

STOP MAKING THE SEATING SO CRAMPED. WE NEED A PASSENGER BILL OF RIGHTS!

The passenger in front of of me reclined their seat back all the way the entire flight. Their headrest was in my face the entire flight! I barely had room for the little plastic cup of water to fit on my tray table; can you make the seats and space between the rows any smaller??? You can’t even get up to use the restroom! Worst flight I’ve had in a very long time!

We had several flights and they were all on-time and flawless

They did not let us board because one member needed a transit visa, which was not evident at the time of ticket purchase.

I was charge a baggage checking fee $68!! I volunteered to check my duffle bag which usually goes under my seat!

I did not like anything because the flight was cancelled yesterday and I did not get to arrive on time in Toronto as I was rebooked with another airline. This caused me to be really stressed out as I am an individual with back injury and to be forced to stay longer in an airport to accommodate a change of airline and the transfers associated with it Due to this I am probably not going to book through your website to eliminate this potentially chaos in the future

shittiest airline in the hemisphere. To improve - start thinking you're flying people, not cattle

Easy boarding, inflight refreshments came on time and comfortable seat

It was good that our flight left early. It was a nice smooth flight and landing.

All good……but luggage didn’t make it on the airplane. Had to wait 3 days. Was a bummer.

Small suitcase used for carryon the last time was refused by boarding crew this time. Appears to be at the discretion and mood of the person on the day. Flight was only half booked, there would have been no problem with space.

It was a problem because there was a delay where we sat before taking off from newark,then when landed in Toronto we sat on tarmac and they wouldn't let us out for a long period of time. When we finally were released to the airport in Toronto the attendant scanned our boarding pass that we were here for our connection to Brazil. We ran all the way to the gate and they said at the gate the door is shut so we can not let you on the plane. We explained that we were checked in by the attendant when we arrived at Toronto airport to go to Brazil and they should not have shut the door. We were ignored at the gate

Flight home was delayed multiple times, did not get home until 2am

Good food, overall very comfy. The flight was full so obviously not optimal, but it is what it is.

Perfect airline, super friendly, great service, tasty food. Would fly again.

Parents with permanently crying baby on board. Neither parents nor crew did anything to calm the baby. The food was extremely disappointing. Seafood stew was very, very small! Not even appetizer size! Seat had a gap in the back. Had to use a pillow to fill it.

Food choices limited & not enticing Seats quite uncomfortable & difficult to control

Definitely get premium economy on a flight this long if you can. Your legs and while body will thank you.

Flight was delayed by several hours and then cancelled due to weather. But Staff was very helpful getting me on a different flight. United should offer food coupons and tooth brush and paste for stranded passengers

I upgraded to the business class cabin. It was the poorest business class I have ever experienced. No access to any business lounge in Tampa airport. Seats are not comfortable. I had a window seat and had to step/crawl over the next seat. Food was mediocre and service below average for business class. Bathroom location was ridiculous. No place to wait. I cannot believe I paid this kind of money and will never fly Lufthansa Discover again. They really should reimburse me somehow.

Boarding was disorganized. The door to one to the toilets wouldn’t lock. The plane was shockingly cramped, and clearly used for domestic flights due to the menus for items to sell domestic travelers. United should be ashamed of its small seats, tiny unclean toilets, and money grubbing stance toward services, compared to Lufthansa, Emirates, and most international carriers United is awful.

Was never allowed on and not refunded the full amount of the ticket plus charged a $300 processing fee.

Terrible. Lost our luggage for 4 days. Did not advise passengers there was a strike in Barcelona Airport and had zero personnel on hand at airport to advise passengers on where to go to file claims. We had to fend for ourselves. No assistance at all other than an online claims submission process that we had to find out about on our own.

Everything you need to know for your flight from St. Louis to Portugal

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