$399 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 7/10. 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.
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Best Portugal Flight Deals from St. Louis

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours

Lisbon
Lisbon2 stops$692
Porto
Porto2 stops$784
Lisbon
Lisbon2 stops$692
Porto
Porto2 stops$784

Cheap Flight Deals from St. Louis to Portugal (STL-PT0)

 
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.

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

Recommended round-trip deals departing in the coming months from the most popular airlines that fly from St. Louis to Portugal.
Discover the best prices for you by selecting your travel dates on KAYAK.
United Airlines Logo
5:30 pm - 9:20 amSTL-LIS
33h 50m2 stops
United Airlines Logo
11:55 am - 11:27 amLIS-STL
28h 32m2 stops
$692United Airlines
Find Deal
Sat, Oct 18 - Sat, Nov 1
United Airlines Logo
4:05 pm - 11:05 amSTL-LIS
13h 00m1 stop
United Airlines Logo
11:55 am - 11:27 amLIS-STL
28h 32m2 stops
$738United Airlines
Find Deal
Sat, Oct 18 - Sat, Nov 1
Air Canada Logo
12:28 pm - 9:35 amSTL-OPO
15h 07m2 stops
Air Canada Logo
6:00 am - 7:57 pmOPO-STL
19h 57m2 stops
$784Air Canada
Find Deal
Mon, Sep 29 - Thu, Oct 9
Air Canada Logo
1:30 pm - 9:20 amSTL-LIS
13h 50m1 stop
Air Canada Logo
11:25 am - 12:25 pmLIS-STL
31h 00m2 stops
$786Air Canada
Find Deal
Sun, Aug 17 - Tue, Aug 26
Iberia Logo
2:42 pm - 9:05 amSTL-LIS
12h 23m1 stop
Iberia Logo
6:35 am - 8:23 pmLIS-STL
19h 48m2 stops
$822Iberia
Find Deal
Wed, Sep 24 - Mon, Sep 29
Iberia Logo
11:38 am - 11:50 amSTL-LIS
18h 12m2 stops
Iberia Logo
6:35 am - 8:23 pmLIS-STL
19h 48m2 stops
$835Iberia
Find Deal
Wed, Sep 24 - Mon, Sep 29
American Airlines Logo
1:22 pm - 11:40 amSTL-OPO
16h 18m2 stops
American Airlines Logo
8:15 am - 8:23 pmOPO-STL
18h 08m2 stops
$837American Airlines
Find Deal
Fri, Sep 19 - Sat, Sep 27
American Airlines Logo
6:00 am - 9:05 amSTL-LIS
21h 05m1 stop
American Airlines Logo
11:05 am - 9:05 pmLIS-STL
16h 00m1 stop
$884American Airlines
Find Deal
Sat, Aug 16 - Sat, Aug 30
Delta Logo
7:05 am - 8:00 amSTL-LIS
18h 55m2 stops
Delta Logo
10:00 am - 8:56 amLIS-STL
28h 56m2 stops
$941Delta
Find Deal
Tue, May 13 - Fri, May 30
Delta Logo
3:40 pm - 5:55 pmSTL-LIS
20h 15m2 stops
Delta Logo
10:00 am - 8:48 pmLIS-STL
16h 48m1 stop
$955Delta
Find Deal
Wed, May 14 - Tue, May 27
Useful Info

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 $659 (return) on average. On the other hand, the most expensive months are June and May, when the average cost of round-trip tickets is $1,482 and $1,254 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 4 weeks before departure. For the absolute cheapest price, our data suggests you should book 25 weeks before departure.


Good to know

Low seasonJanuary
High seasonSeptember
Cheapest flight$399
Best time to beat the crowds with an average 29% drop in price.
Most popular time to fly with an average 9% increase in price.
Flight from St. Louis to Lisbon

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.

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.
8.0
DeltaOverall score based on 7934 reviews
7.9Comfort
8.2Boarding
7.9Entertainment
8.5Crew
7.3Food
Airline reviews

Our bag was lost so that made unnecessary chaos On our trip

6.0 GoodBarbara, Apr 2025JFK - FCO
Read more Delta reviews

Our bag was lost so that made unnecessary chaos On our trip

Delta is my preferred airline. I've traveled with them for years. On time in most cases, good communication, easy to use app. Most planes are pretty nice. I was on a CRJ 700/900 however, which was pretty badly aged inside and needed a refresh. No infotainment, unreliable wifi, best to download before boarding or bring a book. Food choices are really just snacks on this flight, nice variety but about what you'd expect. Great staff and prompt in departure and early arrival too. Overall quite satisfied.

Crew was friendly Love the entertainment in the seat head rest.

Delta flight was on time, seats were comfortable, and crew was nice.

This had nothing to do with Delta… The flights were on time and flawless. The service was excellent. We purchased seats in (aisle/middle) comfort plus since this was a cross country flight. Unfortunately, the woman seated at the window was 300+ pounds and, as might be expected, covered up about a third of the middle seat also. there was absolutely nothing that Delta could have done about that… I just don’t know what the answer should be. If you purchase a seat, you should should be able to use the entire seat and not just the portion that someone else is not sitting/oozing in. Disappointing…there should be something that could be done….I'm just not sure what solution could be.

Delayed take-off. Very small plane so very scary with lots of bumps during the flight. Would never fly Delta on short flights in small 80 seaters plane again! Felt relieved when landed.

The worst part was I was NOT allowed in the lounge even though I was holding a first class ticket and have a premium American Express card. I have flown Business or First Class with many airlines. Delta is the ONLY one who does not extend this courtesy to anyone except people who hold the very expensive American Express card. As a result, I won’t fly Delta if I have any other choice.

It was an overnight flight and I desperately needed coffee before we landed, but Delta does only one beverage service, and that is shortly after takeoff, not before landing at 5 am.

A little bumpy ride . No food was being provided due the the turbulence. That was ok it was a short flight to my standards.

Simply outstanding. Their new lounge for Delta One customers is a cut above the rest.

Everything is good except the dinner and breakfast. The sandwich is very delicious. Toilet is clean, I only use one of them. Flight attendants are very nice. 👍👍

A bit rush for transit. Food and entertainment are not available

Boarding was a little difficult. The gate area at O'Hare was very small and crowded due to multiple gates in the area. Could not hear the intercom, so had to rely on signage to see when my group was boarding and the signage was blocked by passengers standing in the gate. Flight was great and we arrived in Montreal on time.

Multiple delays and not straight answer from the United team

For economy, it was very good. Staff was great, they even let some of us change seats for more leg room... Put an empty seat between us which was fantastic for a 12hr flight. Onboard entertainment was excellent, I think over 200 choices of movies/tv/etc The bad was the barely/nonfunctional wifi that cost either $16.99 or 1700 miles (full flight). It was atrocious... Definitely the worst of the last 3 long haul major airlines I was on the last few months.

Stewardess spilled orange juice on my clothes/seat no help no apology just threw napkins at me to clean the mess up. Not Happy.

Smooth flight. Boarding was chaotic. Could not hear the gate agent over the intercom. People were lined up in the wrong lines. Groups one and two were told to board through line one and group 3 through line 2. All very confusing. Once in the air, the flight was smooth. There was no entertainment option on this aircraft, even though it was a larger aircraft.

The plane pushed back from the gate on time. However, it stopped on the ramp, and we waited for over 20 minutes before the aircraft pulled back to the gate. Apparently, something of importance had to be removed from the aircraft by the gate agent. I found this to be odd. The delay was not significant, but I felt that whatever was on the aircraft that had to be taken off, should’ve been done before we pushed back from the gate.

I didn’t get on plane. Passport being processed by consulate with visa application. Tried to cancel through underpricer after purchasing cacelling for any reason. No dice, they are thieves.

Electric plugs didn't work. Entertainment system wasn't working

Several delays. Next flight was worse. Did not arrive home until 2am PT

Very helpful ground crew after an earlier flight delay and being rebooked on a different flight.

Everything about the flight was lovely…We left early, arrived early, cabin crew were efficient and helpful. Flight was easy and most pleasant.

First world problems, but still… We were seated in first class and asked for a cocktail on a very short, 50 minute flight. After our drink order was taken, a half hour went by, and we noticed that every other person in the small plane had been served except for us. We got up to ask about it, the drinks finally came, then were taken away three minutes later since the flight was so short. Really strange situation, on the other hand, we were in Utah.

We missed our flight. The boarding pass had the wrong gate and by the time we received the text from Kayak, our flight was already gone. I’ll never use Kayak again and will go direct to the airlines in the future.

Boarding took forever, the plane was cramped and cold, and the seatbelt song came on constantly throughout the red eye flight with a loud pre-recorded message playing each time

Cabin felt crammed Snacks are lame But crew was super efficient getting us out on time despite delay

Took off on time and successfully avoided weather that looked to be a problem along the way

There were five broken seats on the plane. The crew was very rude in telling people they had to get off the plane and get a flight the next day. No call for volunteers, but telling people they had to get off. One woman was flying with her elderly mother and daughter and was told she had to leave or all three had to leave. Fortunately, a volunteer offered to stay. The situation was handled poorly.

The flight to Tokyo AA61 took off about two hours late, but then had to turn back. By that time the crew had to be replaced. Then they kept promising to take off in an hour, then in 3, then switch to the next day.

All was good except for the seats, not very comfy.

2.5 hour delay sitting in the plane on the tarmac, you tell me how the experience was

I hope these comments will find their way to AC customer experience team. Me and my spouse 50 years of aged coming back from 7 days perfect vacation... While boarding in FLL flight AC1621, one of the boarding agents (tall aged african american) man literelly yeld at my wife during the picture talking process. MAM ! STEP !! BACK !!! We are not illegal immegrants beying deported, nor are we in the millitary. We are customers returning home. This was unacceptable. While boarding in YYZ flight AC1154, one of the boarding agents (tall aged caucasian) man criticied with several complesant remarks my passport condition saying that I could not travel intl with it due to stain, decoloration, and BLOOD. My passport does not have blood on it! Yes it might be in less than perfect condition, but their are ways to talk to customer that does not imply not allow a boarding agent to be angry fathery like, or a custom agent looking at a suspicious individual. Both experience were less than acceptable for might I remind you a paying CUSTOMER returning home.

Short flight so no food or entertainment. Good landing at SFO and on time. We were told no carryon luggage yet lots of people were puting bags in overhead compartments. The rules need to be made more clear. I was on the first leg of an international flight and this is the first time I could not have carryon luggage.

This flight didn't happen for me because of overbooking.

My flight was overbooked and they would not let me board. I had to book another flight and pay the full amount of that flight. I did not get any help at all from Air Canada or United Airlines.

Comfortable seats and movies entertainment available. Better experience than the flight from Toronto to Denver.

Crew was pleasant and efficient. The speaker system for instructions was hard to understand

Poor air traffic controller staffing led to a 50%reduction on flights so we got to wait 4 hrs for our flight! Very disorganized at the gate Poor communication with customers

It was delayed by almost 90 minutes and that messed up our plans but it was beyond UA’s control that is what we heard

The seats were way too crowded. Just because I do not have the luxury of a suite, does not mean that I want to fly from Austin to London scrunched between two people and the seat in front of me in my face. Ridiculous. I should have flown with Turkish Airlines...

We travelled with Level, which is a subsidiary of Iberia. They mixed up all our seats, downgraded few from premium economy fo economy. The crew were not professional, they seem to be in a rush! Also some with an attitude

Paid for “extra room” selected seat. Wasn’t a benefit. Also was in aisle and was bumped almost every time attendants walked down aisle. Should have saved the assigned seat money and let them select.

Everything OK , except the plane left more than an hour late so I couldn’t participate in an excursion I had that morning in Brcelona

Flight from Madrid to Dakar had no onboard entertainment for a business class. Not even a single screen . That was disappointing. The WiFi only worked for the first 45 mins of the flight.

very good all round. staff, food, entertainment, punctuality all very good

The cabin crew were great very helpful and accommodating. We had a fellow passenger throw up next to us. The flight crew did an amazing job cleaning up and reseating us. We did question as to if he should have been let on the flight as his condition was likely self imposed.

online check-in was horrible and didn't work either way

Horrible. Paid for seats for my family. Iberia changed planes and never notified us that the seats we paid extra for did not even exist on the plane. We were randomly placed on the plane. Thankfully, we were seated together. Upon boarding, my youngest daughter was pulled from the line and they just arbitrarily changed her seat 7 rows back from the rest of the family. I had to wait at the gate while they tried to see us back together. One of the most uncomfortable small spaces on a plane I’ve ever experienced. When I called Iberia, they first told me that no mistake was made that the plane was never changed. Yet my receipt for my paid seats were for rows that did not even exist on this type of plane we were getting on. They said that they would reimburse my money and I would get an email, but I’ve never received any information or emails regarding a refund for the seats that I had paid extra for. Then when we arrived in Madrid, one of the pieces of luggage that we had checked in was damaged to the point that the handle that was stowed in to the luggage was broken off by the crew members handling the luggage. The crew on the plane was very nice, but as far as the rest of the experience, I would be very hesitant to ever use Iberia again.

The airline refused to board me because I showed up only 50 minutes prior to departure time, despite the fact that shortly before that, when I arrived at the airport still in time, they changed the terminal and I had to take a bus that took 20 minutes. Keep in mind that for some maintenance error I could not check in online like I usually do. Personnel at the airport was unable to let me in, customer care was beyond useless, the original airline operator (Iberia) was as useless as a toilet paper roll core in time of a wipe and all this uselessness made me waste my ticket, my reservations, my long time parking, food and most of all the joy of being with my family for the new year after working my bottom off even at Christmas. Am I happy? Come and ask me in person!

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