$304 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 9/21. 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

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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$590
Porto
Porto2 stops$601
Lajes
Lajes3 stops$1,094
Lisbon
Lisbon1 stop$590
Porto
Porto2 stops$601
Lajes
Lajes3 stops$1,094

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

Wed, Dec 31 - Thu, Jan 15
United Airlines Logo
8:15 am - 10:15 amSTL-LIS
20h 00m1 stop
United Airlines Logo
10:55 am - 10:52 amLIS-STL
29h 57m2 stops
$590United Airlines
Find Deal
Wed, Dec 31 - Fri, Jan 16
United Airlines Logo
9:55 am - 8:10 amSTL-LIS
16h 15m2 stops
United Airlines Logo
5:00 am - 1:55 pmLIS-STL
14h 55m1 stop
$591United Airlines
Find Deal
Mon, Nov 10 - Fri, Nov 21
Iberia Logo
9:47 am - 4:00 pmSTL-OPO
24h 13m2 stops
Iberia Logo
8:20 am - 7:27 pmOPO-STL
17h 07m2 stops
$601Iberia
Find Deal
Tue, Jan 6 - Fri, Jan 16
Air Canada Logo
8:05 am - 9:20 amSTL-LIS
19h 15m2 stops
Air Canada Logo
11:20 am - 3:29 pmLIS-STL
34h 09m1 stop
$605Air Canada
Find Deal
Mon, Jan 5 - Thu, Jan 15
Air Canada Logo
6:35 pm - 9:20 amSTL-LIS
32h 45m2 stops
Air Canada Logo
10:55 am - 10:52 amLIS-STL
29h 57m2 stops
$606Air Canada
Find Deal
Tue, Oct 14 - Wed, Nov 5
American Airlines Logo
9:35 am - 7:35 amSTL-OPO
16h 00m2 stops
American Airlines Logo
8:20 am - 8:23 pmOPO-STL
18h 03m2 stops
$608American Airlines
Find Deal
Mon, Nov 10 - Wed, Nov 19
Iberia Logo
9:47 am - 4:00 pmSTL-OPO
24h 13m2 stops
Iberia Logo
4:40 pm - 7:27 pmOPO-STL
32h 47m2 stops
$612Iberia
Find Deal
Tue, Oct 14 - Wed, Nov 5
Lufthansa Logo
12:25 pm - 10:25 amSTL-OPO
16h 00m2 stops
Lufthansa Logo
6:00 am - 1:55 pmOPO-STL
13h 55m1 stop
$640Lufthansa
Find Deal
Wed, Nov 12 - Tue, Nov 18
Lufthansa Logo
3:50 pm - 11:40 amSTL-OPO
13h 50m1 stop
Lufthansa Logo
4:15 pm - 1:55 pmOPO-STL
27h 40m1 stop
$641Lufthansa
Find Deal
Fri, Nov 14 - Sun, Nov 16
American Airlines Logo
11:51 am - 11:45 amSTL-OPO
17h 54m2 stops
American Airlines Logo
12:25 pm - 11:13 amOPO-STL
28h 48m2 stops
$902American Airlines
Find Deal
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 November, when tickets cost $632 (return) on average. On the other hand, the most expensive months are June and August, when the average cost of round-trip tickets is $1,327 and $1,216 respectively.

What’s the cheapest day of the week to fly from St. Louis to Portugal?

The average price of all round-trip flights from St. Louis to Portugal clicked on KAYAK for each day over the last 12 months.

When flying from St. Louis to Portugal, you should consider leaving on a Monday and avoid Thursdays if you are looking for the best rates. For your return to St. Louis, you’ll find the best rates on Mondays and the most expensive ones on Fridays.

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 3 weeks before departure, which saves you about 47% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 8 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$304
Best time to beat the crowds with an average 30% drop in price.
Most popular time to fly with an average 5% 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.

  • What is the cheapest time of day to fly to Portugal?

    The cheapest time of day to fly to Portugal is generally in the afternoon, when round-trip flights cost $884 on average. Morning departures are around 2% cheaper than evening flights, on average. The most expensive time of day to fly to Portugal is generally in the evening, which is peak travel time and where the average cost of a ticket is $1,083.

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.
7.4
United AirlinesOverall score based on 8944 reviews
6.6Food
7.7Boarding
8.1Crew
7.1Entertainment
7.3Comfort
Airline reviews

All of the United employees I interacted with were professional and courteous. The aircraft was clean, the food on the flight was good. No complaints here.

10.0 ExcellentCraig, Aug 2025SLC - EWR
Read more United Airlines reviews

All of the United employees I interacted with were professional and courteous. The aircraft was clean, the food on the flight was good. No complaints here.

I had no checked baggage but was required to hand over carry on baggage at the door of the plane. There was a lot of overboard space in the plane and I was one of the last ones. I ran to get my carry on but it was gone. I was given back at the plane door in Toronto, so the wait was not as long as it would have been at the carousel.

Armrest controller on my seat 35D and nextbooennseat 35E did not work right. Hard to press buttons to recognize and 35D had constantnpressure either upmost down somit was nearly impossible to make selections. .

I flew with my dog and had already purchased my dog’s ticket. Even that morning I had called costumer service to insure that my husband and I had seats together since the website was giving me an error when choosing our seats and the representative mentioned our dog. I showed up early to the airport and when I got to the gate and we started boarding I was help back and told that I was supposed to have a yellow tag and that I should have checked in at the counter for them to give me that tag. I was not aware of this, the representative on the phone did not say anything. Nor did I see it anywhere in the checking process online, so if you travel with a pet and are not checking in luggage, just know that you still have to go to the check in counter when arriving at the airport unless you want to be the last one to board and not have room for your carry on in the overhead bins. Other than that, I had a great experience.

Once we got in the air the pilot made up some of the time of the delay. So that was really nice.

We had a layover from YVR to Denver. We bought 4 bottles of Absolut Vodka at the YVR Duty Free for $116.20, after going through security and American Customs Pre Clearance at YVR, Vancouver. When we landed in Denver, United put us behind the American Customs as well as TSA again for some reason. We were forced to go through American Customs and TSA again. TSA confiscated our rightfully owned Duty Free Absolut Vodka bottles. Because United incorrectly forced our flight behind American border and TSA again, we missed the connecting flight. After United put us on a later flight, we eventually arrived in Chicago very late, with hardly any sleep. I am looking for compensation from United for our incorrectly confiscated Absolut Vodka bottles worth $116.20, as well as compensation for incorrectly putting us behind American Customs and TSA again, causing us to miss our connecting flight, making us arrive extremely late in Chicago.

From the first moment you interact with United Airlines, you can expect nothing less but extreme frustration. The baggage handler at the bag drop seems completely unbothered by the presence of customers waiting in line. No help was extended to load the baggage whatsoever. And if any of your bags is overweight by 0.01 pound they will make you re-distribute everything in your suitcase just to play power trip. When it was time to board no help was extended to customers to locate their seats. Moreover. It was a chaotic mess at the gate when it was unclear who should board first and everyone just bunched up, trying to get on the plane. I am sure the crew was doing their best to perform their jobs while being paid their wages however it shouldn’t be that hard to smile once or twice when you’re in the business if serving customers. It is a shame for the United States of America to have a flagship carrier of such low caliber. Our flight was also delayed by about an hour and a half due to further delays prior to our inbound flight. Being someone who has travelled for both business and leisure in Asia, Europe, and South America I have never experienced such poor quality of service.

Very small cramped plane for an international flight. Everything else was good, but it was maybe the smallest comfort-wise I've ever been on for longer than 3-4 hours and the trip was 7.5

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

There was no food available for this red eye... one little waffle cookie for a 6+ hour flight... thank God I was able to sleep some

We arrived 4 hours early and still almost missed the flight because they weren’t able to access one of the boarding tickets. They then sent hour bags late and we were all of our without clothing and eventually had to take an expensive cab back and forth to the airport as they wouldn’t deliver the bag which arrived late at night that day and we would have to wait until noon the began day (messing up a second day of plans). Also, all the food has dairy or pork. No vegan or even vegetarian option in the flight—even for purchase.

The flight was canceled 3 hours after original take off time

My flight was delayed for several hours. Sitting at gate 16 for several hours, I got a text from Kayak the gate changed to 9 before it was announced. Very bad communication at each gate from American Airlines employees. I received 10 notifications of delay from Kayak. My vacation started off horrible! I will write to American Airlines corporate office also.

The AA staff person who checked our bags was curt and almost rude. The FA also seemed unhappy doing her job. Overall it was like riding the school bus back in grade school.

Internet was a bit expensive and did not work ask that week otherwise a good flight

Ring in first class for an overnight flight, there was no blankets nor pillows for first class customers.

My Internet did not work for Outlook email or basically anything. I paid for one hour of in-flight usage and it was terrible. I spent a lot of time on different sites and browsers with no luck and a lot of frustration. Other than that, the flight was on time, crew was nice, service was fine. Seat was OK even though I paid for the extra 6 inches. I cannot imagine how tight the seats in the back must be.

Delayed flight that lead to a missed connection and a 5-hour trip became a 12-hour flight 🙄

Any flight to ORD after about 2pm this summer has been challenging. Flight was delayed getting in (coming from ORD) and that led to it not leaving before a ground stop due to lightening before they could fuel the plane, and so forth. They made up some time but we were still late in arriving at ORD, and that led to missed connections.

Food was ok, but not as good as I have had before on AA.

I found the boarding easy and my seat was very comfortable as I had a lot of leg room. I am not too happy that I no longer have lounge access even though I used to get it with my TD credit card.

Flight cancelled. Major disruption to our travel. Do not use Air Canada from KC. To few flights.

Real smooth and easy, Real good leg room in coach!

There labor disputes cancelled my flight less than 24 hours before my boarding time but there customer service/website was easy enough to navigate and they rebooked me for no upcharge.

Re luggage I carried a backpack only. I did not check any bags in. However there were other passengers with carry on luggage going in the plane. My question is why are others allowed to have a carry on luggage inside the plane? Shouldn’t they have dropped it off at the gate? I’m asking because I could have brought the same thing instead of a backpack only. Please clarify for future reference. Thank you.

Like the service. Very hard to communicate or contact when have problems

Very bad, flight was cancelled due to strike and staff was unable to rebook us

They rescheduled me and I had no issues with the new flight

Air Canada is my new fave airline..I plan to use when I can. No complaints at all just rave compliments for the staff and airline.

Strike pissed me n stranded in middle of no where

The crew were not very personable. The crew did not serve tea or coffee. The bathroom was not kept clean. Two out of the 5 toilets in the cabin weren't working.

It was extremely cold in the back of the plane. The seats are uncomfortable and space very small. Crew was excellent as usual.

Check in needed to be in person, not nice. Also I won’t do connections in Charlotte again because you need to go through security again and short connections become a problem

Iberia lost my bag, said they found it in another country, said they sent it to me, but never did. Went my whole trip without my stuff, but expecting it to show up because that’s what they said would happen. Their communication sucks, their website sucks, and to top it all off, their seats are small and uncomfortable. They’re bad at their jobs and they should feel bad about themselves. Do not even get me started on the flight home. AVOID!

I described my experience in the previous window. I didn't realize that there would be another opportunity for this flight. Please look at my response in the previous window.

Boarding was 2 1/2 late no explanation Captain said he did not know why, but he rested at home for an extra couple of hours. Food was edible, Nothing more.

I liked the comfort of the plane. It was unexpected from past experiences.

BEWARE!!! Iberia changes your seats at random. I paid for a window seat and they changed it to one in the middle aisle resting against the bathroom- can’t lean back + hear every flush. This on a 11 hour flight.. There were families that were broken up with separate seats all over the plane. Lots of upset passengers showing their seat confirmation to the besieged and helpless airline steward. Also, the gluten free meal was tasteless.

Chair is very high. Your feet cannot touch the ground for 8 hours flight. It was a nightmare. Food was bad.

ground crew and check-in was pathetic - insisted on charging me for luggage even though the ticket said it was already included. They also accidentally sent my luggage through without a luggage tag and had to retrieve it. Generally, it was like a bad movie.

The plane was delayed by two hours in Chicago which led to us missing the next flight. Lufthansa rebooked the flight and booked us a hotel for the night in Frankfurt. The level of customer service and getting us taken care of was superb. The flight crew and the service on the ground was superb.

It was a short flight, everything was good with it.

Flight was delayed over one hour and I had to pay to select my seat, even though my booking supposedly had free selection (I paid extra for this at time of booking)

Stop charging for alcohol overseas flights and start taking cash again not everyone wants to pay with card if the person is bigger give him seat on the outside seats not the middle in between the people is common sense and mainly if you fly for Lufthansa provides the sam service and experience...

good entertainment package but rather small seats for business class

The male attendant has zero personality. It seemed like he was over worked or hated his job, not once did he smile or made any contact with the people on the plane. Strictly business and call it a day!

Booked Economy but it translated to economy light for Lufthansa so now we are stuck paying an extra $75 per person both ways for our checked bags. If I had known that, I would have never booked these tickets because it came out to be more than other options. The booking in the kayak side clearly says Economy and has a link to the inormation for Lufthansa which states Economy included a checked bag. Super annoyed about that.

The flight from Dulles to Munich was just okay. The seats were comfortable and extra foot room was noticeable in comfort plus. Disappointed in the booking in so much I requested an aisle seat and then was assigned a middle seat. The food was inedible. Movie choices were moderate. I usually fly Delta, but this WA flight was cheaper. Next time, I'll happily pay the extra to fly Delta.

Flight was late arriving. So, we left 25 min late. Pilot made some time up during the flight. Therefore, we arrived alittle past original time.

Food is too little (in volume) and too spicy.. There are no snacks in the back of the plane in between meals.

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