$317 Find Cheap Flights from St. Louis to Portugal - Compare and Save

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
Lisbon2 stops$776
Porto
Porto1 stop$737
Lajes
Lajes2 stops$1,302
Lisbon
Lisbon2 stops$776
Porto
Porto1 stop$737
Lajes
Lajes2 stops$1,302

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, Nov 4 - Wed, Nov 11
Lufthansa Logo
3:40 pm - 11:45 am
STL
-
OPO
14h 05m
1 stop
Lufthansa Logo
6:00 am - 1:45 pm
OPO
-
STL
13h 45m
1 stop
$737Lufthansa
Wed, Nov 4 - Wed, Nov 11
Lufthansa Logo
1:27 pm - 11:55 pm
STL
-
OPO
28h 28m
2 stops
Lufthansa Logo
6:00 am - 1:45 pm
OPO
-
STL
13h 45m
1 stop
$743Lufthansa
Sun, Dec 6 - Thu, Dec 10
United Airlines Logo
7:30 am - 9:30 am
STL
-
OPO
20h 00m
1 stop
United Airlines Logo
6:00 am - 11:25 pm
OPO
-
STL
23h 25m
2 stops
$745United Airlines
Tue, Dec 1 - Tue, Dec 8
United Airlines Logo
6:15 am - 9:30 am
STL
-
OPO
21h 15m
2 stops
United Airlines Logo
6:00 am - 3:30 pm
OPO
-
STL
39h 30m
2 stops
$748United Airlines
Sun, Dec 6 - Thu, Dec 10
United Airlines Logo
6:15 am - 9:30 am
STL
-
OPO
21h 15m
2 stops
United Airlines Logo
6:00 am - 12:34 am
OPO
-
STL
24h 34m
2 stops
$750United Airlines
Sun, Dec 6 - Tue, Dec 8
United Airlines Logo
6:30 am - 9:30 am
STL
-
OPO
21h 00m
1 stop
United Airlines Logo
12:35 pm - 7:40 pm
OPO
-
STL
13h 05m
1 stop
$754United Airlines
Wed, Nov 4 - Tue, Nov 10
Air Canada Logo
6:40 am - 11:00 am
STL
-
LIS
22h 20m
2 stops
Air Canada Logo
1:00 pm - 2:18 pm
LIS
-
STL
31h 18m
2 stops
$792Air Canada
Wed, Nov 4 - Tue, Nov 10
Delta Logo
9:45 am - 8:00 am
STL
-
LIS
16h 15m
2 stops
Delta Logo
5:00 am - 4:50 pm
LIS
-
STL
17h 50m
2 stops
$793Delta
Fri, Oct 16 - Mon, Oct 19
Multiple Airlines Logo
2:40 pm - 6:50 am
STL
-
OPO
34h 10m
2 stops
Multiple Airlines Logo
7:20 pm - 8:00 pm
OPO
-
STL
30h 40m
2 stops
$850Multiple Airlines
Fri, Nov 6 - Tue, Nov 10
Air Canada Logo
4:15 pm - 11:00 am
STL
-
TER
37h 45m
2 stops
Air Canada Logo
11:50 am - 3:30 pm
TER
-
STL
56h 40m
2 stops
$1,302Air 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 September, when the average cost of round-trip tickets is $791 and $766 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 10 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$317
Best time to beat the crowds with an average 42% drop in price.
Most popular time to fly with an average 15% 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.
7.8
DeltaOverall score based on 8419 reviews
8.1Boarding
7.8Comfort
8.5Crew
7.2Food
7.8Entertainment
Airline reviews

We sat on the runway for over an hour before departure. That was unwelcome.

6.0 GoodAnonymous, Jun 2026
SEA - SFO
Read more Delta reviews

We sat on the runway for over an hour before departure. That was unwelcome.

Horrible. Faucet in sink not working, wifi not working. Didn’t bring food or snacks

Flight was delayed before take off and at landing. Baggage took 20 minutes. Flight crew would not serve full soft drink and had to ask multiple times before receiving water.

From checking to boarding, it was a seamless experience. The service agents were so helpful. The flight crew was so pleasant.

Gate agent showed up 20 minutes before boarding and was not at all friendly. Had to take this flight due to the one on the day before being cancelled and any later options were already full with long standby lists. Despite having paid for Delta Comfort seats, Delta did not allow me (or anyone) to choose their seat. The agent assigned them for everyone just prior to boarding. Self seat selection was allowed on the original flight. Flight staff was great - very friendly.

Flight attendants were great. Cheerful, upbeat and friendly. Jet, in particular, was fantastic.

I have Precheck. Flew HPN to DEN and return this past weekend. Delta didn't attach my Precheck number to this trip. So it was waiting in general line especially in Denver. Unavailable.

Original flight was delayed, then cancelled and the gate staff did not expedite rebooking. Also, no instructions were given that a ticket number was needed before being called to facilitate rebooking. This could have been much more organized.

Be on time? When not on time a circling for over an hour offer more than 1 bag of chips to the passengers? It was a 7 hour flight by the time we got done.

Five hour delays every hour, I wish it were all at once

Very easy ! Use the kiosk and bag drop and right to security within 10 min

Checking bag at terminal was horrible. No agents to check us in and only 1 kiosk working. Boarding went ok. Crew onboard was very scattered rained. Missed our row while serving and then didn’t see them hardly again.

Crew was amazing, takeoff wonderful. The bathroom was disgusting from before takeoff the odor made the flight uncomfortable as you could smell the bathroom from the center of the plane where we were sitting. Smelled like raw sewage. My daughter was throwing up as we landed due to the smell and horrible turbulence as we approached Newark.

Airline tickets are not cheap. You expect reliable competent service. Thanks to canceled flights and botched transfers we arrived at our destination two days late. This is not acceptable

Horrible! Several delays and then was cancelled! I spent over 24 hours in the airport and was unable to get a hotel or food voucher.

The entertainment they offer could use some games, and maybe they could add some cookies to the snack menu. And the automated messages are a bit repetitive. But it was comfortable temperature wise and the seats were comfortable. The crew is very polite and helpful

The entertainment is a bit limited, it would be better if they added some games to play besides the movies and tv shows. But the seats are comfortable and the crew is polite

This planes staff was top tier. Everything went great and had a great flight home.

Food was great. Staff was phenomenal. Seats were a bit hard and could use a lot more entertainment options as far as movies to choose from. WiFi was good. Overall great trip.

This was an overnight flight, and in the morning they did know coffee service. How you can throw passengers in a San Francisco airport at 5:40 a.m. in the morning and not giving them Coffee is a crime.

Excellent service. Flight attendance like Jessica,, on our flight, is a reason I wouldn’t mind flying through British Airways again. Jessica,, was very courteous and helpful.

The seats were extremely cramped, with very little legroom or personal space. There was no room left in the overhead bins for a backpack, and the space under the seat in front was so limited that I could barely fit my bag underneath. Overall, the seating arrangement felt very uncomfortable and overcrowded.

Significant delays on my trip to Chicago and my trip back to NY

Terrible boarding and first class experience. Nice staff but overall disorganized, dirty plane.

Delayed by 5 hours and I had to wit in the airport for more than 6+ hours.

weather delay of almost 2 hours then we landed and our gate wasn't available so we waited another 30 min

Flight had mechanical issues and it was delayed 30 mins - some of us boarded and then had to deplane.

technology worked well and everything ran smoothly. The seats are quite cramped so please don't try to re-engineer the cabin to squeeze more bodies on board.

Delayed flight more than I hour. When boarding we spent some additional time on the plane before takeoff ....

Flight was delayed due to connecting passengers. Lack of snack options bad. Sitting in Aisle, last cart run pulled the cart directly into my knee. Rude awakening.

1didnt have wheel chair I ordered wheel chair in my ticket flight

Flight was overbooked and seats assigned to multiple passengers. Delay 1 hour to sort out.

Good but I don’t received my bags yet is been 5days still no update

It was pretty straight forward, no glitches or hidden costs

It was a short flight so, everything went smoothly and we got to where we needed to be safely.

Didn’t make it on the flight. Delayed then had to be rebooked, which in turn had me waiting at the airport for another 8 hours before next flight

No TV on the flight. The charging outlet was not working. No food, even a sandwich. The served orange was poor quality.

Selected seats 5 months prior to date. Had email confirmation and seats were not honoured. Family did not sit together

Loved and was pleasantly surprised by the food!! Request Lufthansa to help transiting passengers at Munich (confusion whether to go thru passport control or not).

The flight was comfortable and the staff were helpful and friendly. However, we did not know we were flying PAL until we arrived in Canada, so it was a bit disconcerting. In addition, which port we were leaving from was confusing.

We sat in our seats on the tarmac for almost 3 hours due to storms. They would not give us water or a snack. We were to depart at 7.30 pm and it was about 10.30 when we took off. No dinner until much after that. Beef type noodle dish was terrible with about a teaspoon of beef in it. The breakfast sweet waffle with egg and sausage inside was horrible. An English muffin sandwich would have been much better. Food was the worst in all of our years of traveling the world.

Our screen kept turning off ...3 times...had to get crew attention to turn it on again

They messed up my seat so I didn’t get the one I paid for

Put me on standby; flight was late; missed my connecting flight; disaster

Flight attendants were fine, seats a bit hard but I use a cushion for extra support. The only issue was it was a bit too cool and I needed to ask for and received and extra blanket. I survived!!!

Very few things and/or people are excellent. It was very good.

Extremely uncomfortable seats. Experience was like a Frontier Airlines flight. Would not fly it again.

Very, very tight legroom. They must’ve jammed in an additional few rows of seat seating. Denver to Munich was the least legroom I’ve ever had on any flight, let alone a multi hour international journey. I will not take that flight again.

In my first flight with Air Canada we sat in the plane for 4:00pm to 6:30pm. Finally we were asked to get off the plane and we were told the flight was cancelled after 7:00pm There was o clear explanation of what was the problem. I was booked without my permission on a Delta Flight at 7:30pm that was leaving at 8:00pm and I still had to go get my luggage(my final destination was Rome with one stop in Toronto. The luggage claim for Canada was closed so had to return to finally get it on the luggage belt.. Of course I missed the Delta flight and all the next day flights were booked. I also lost what I paid for my stay in Rome because I did nt cancel in time. A complete nightmare.

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

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

Information on your arrival and departure airports