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Portugal

$302+ Cheap flights from St. Louis (STL) to Portugal

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/19. Fares are subject to change and may not be available on all flights or dates of travel.
STL — LIS
oct. 25 — nov. 11
sáb. 10/25
sáb. 11/1
1 adult, Economy
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Cheap flight deals from St. Louis to Portugal

Keep the following information in mind while searching for St. Louis to Portugal flight deals. Data was last updated septiembre 25, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$526
(Mytrip)

One-way from

$302
(Kiwi.com)

Popular in

June

Cheapest in

November

Average price

$1,059
Provider with most accurate pricing for Lambert-St Louis-Lisbon Humberto Delgado flight deals.
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Provider most trusted by Cheapflights users for Lambert-St Louis-Lisbon Humberto Delgado flights.
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From Lambert-St Louis to Portugal
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One-way flight from Lambert-St Louis to Portugal
Search Deals
Highest demand for flights based on searches. 20% potential increase in price ($233 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease ($37 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from St. Louis to Portugal

Cheapest flights from St. Louis to Portugal
Explore the most affordable flight options available from St. Louis to Portugal. Find the lowest fares from popular airlines and budget airlines, with prices last updated on septiembre 25, 2025.

This Mytrip deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/229:15 amSTL - LIS
2 stops18h 05mMultiple Airlines
mié. 11/195:00 amLIS - STL
1 stop14h 55mMultiple Airlines
Deal found 9/23$526
This Mytrip deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/229:15 amSTL - LIS
1 stop19h 50mMultiple Airlines
mié. 11/55:00 amLIS - STL
1 stop14h 55mMultiple Airlines
Deal found 9/23$531
This Air Canada deal was found by Cheapflights users on 9/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/174:05 pmSTL - LIS
1 stop11h 15mAir Canada
jue. 12/410:55 amLIS - STL
2 stops31h 20mAir Canada
Deal found 9/22$534
This United Airlines deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 11/410:00 amSTL - LIS
2 stops18h 15mUnited Airlines
mié. 11/195:00 amLIS - STL
1 stop14h 55mUnited Airlines
Deal found 9/23$535
This Delta deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 11/134:30 pmSTL - LIS
1 stop10h 25mDelta
dom. 11/235:00 amLIS - STL
2 stops24h 23mDelta
Deal found 9/24$538
This Air Canada deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 11/1810:00 amSTL - LIS
2 stops17h 20mAir Canada
mié. 2/411:20 amLIS - STL
2 stops33h 10mAir Canada
Deal found 9/23$539
This United Airlines deal was found by Cheapflights users on 9/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 10/194:05 pmSTL - LIS
1 stop13h 00mUnited Airlines
mié. 11/55:00 amLIS - STL
1 stop14h 55mUnited Airlines
Deal found 9/22$541
This United Airlines deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/1211:20 amSTL - LIS
2 stops16h 55mUnited Airlines
mié. 11/195:00 amLIS - STL
1 stop14h 55mUnited Airlines
Deal found 9/23$543
This Air Canada deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/264:05 pmSTL - LIS
1 stop10h 50mMultiple Airlines
mar. 12/25:00 amLIS - STL
2 stops40h 29mMultiple Airlines
Deal found 9/24$546
This United Airlines deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 11/238:25 amSTL - LIS
1 stop19h 50mUnited Airlines
jue. 12/410:15 amLIS - STL
1 stop13h 14mUnited Airlines
Deal found 9/24$547
This United Airlines deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 10/275:58 pmSTL - OPO
1 stop10h 32mUnited Airlines
mié. 11/126:00 amOPO - STL
1 stop13h 55mUnited Airlines
Deal found 9/25$573
This Kiwi.com deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/294:50 pmSTL - OPO
1 stop17h 35mLufthansa
mié. 11/196:00 amOPO - STL
1 stop13h 55mLufthansa
Deal found 9/23$580

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Portugal that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 25, 2025.
Use the filters below to find and compare flights from St. Louis to Portugal that are best for you.

Fly from

St. Louis

Fly to

Portugal

Route

Depart

Return

Price

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mar. 11/4

10:00 am-10:15 am

2 stops18h 15m

Lisbon Humberto Delgado

mié. 11/19

5:00 am-1:55 pm

1 stop14h 55m

$535

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

jue. 2/12

6:45 am-8:00 am

2 stops19h 15m

Lisbon Humberto Delgado

dom. 2/22

5:00 am-11:10 pm

2 stops24h 10m

$543

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

vie. 1/16

12:00 pm-8:00 am

1 stop14h 00m

Lisbon Humberto Delgado

sáb. 1/31

5:00 am-4:50 pm

2 stops17h 50m

$544

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mar. 3/17

3:15 pm-10:15 am

2 stops14h 00m

Lisbon Humberto Delgado

mar. 3/24

5:00 am-9:04 pm

2 stops21h 04m

$553

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mar. 11/4

10:00 am-10:15 am

2 stops18h 15m

Lisbon Humberto Delgado

mar. 11/18

5:00 am-9:54 pm

2 stops22h 54m

$553

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mié. 12/3

6:06 pm-8:00 am

2 stops31h 54m

Lisbon Humberto Delgado

dom. 12/7

5:30 am-5:57 pm

2 stops18h 27m

$559

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mié. 3/11

10:30 am-10:15 am

2 stops18h 45m

Lisbon Humberto Delgado

mié. 3/18

11:55 am-9:48 am

1 stop26h 53m

$565

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

lun. 10/27

5:58 pm-9:30 am

1 stop10h 32m

Porto

mié. 11/12

6:00 am-1:55 pm

1 stop13h 55m

$573

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mié. 11/19

7:00 am-8:10 am

1 stop19h 10m

Lisbon Humberto Delgado

dom. 11/23

5:00 am-1:55 pm

1 stop14h 55m

$581

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

mié. 1/21

1:00 pm-8:10 am

2 stops13h 10m

Lisbon Humberto Delgado

dom. 1/25

5:00 am-1:55 pm

1 stop14h 55m

$581

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/22

Showing 1-10 of 30 results
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Best time to book a flight from St. Louis to Portugal

Have a flexible travel schedule? Discover the best time to fly to Portugal from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

What is the cheapest month to book a flight from St. Louis to Portugal?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Portugal (average of $612). Flying from St. Louis to Portugal in June is currently the most expensive (average of $1,126). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to PT?

Find hourly flight availability from St. Louis to Portugal. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated septiembre 25, 2025.

When flying from St. Louis to Portugal, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Reviews of airlines servicing Portugal

Get insights into the airlines that provide service to Portugal. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Portugal. Reviews last updated septiembre 25, 2025.
Read through reviews of airlines operating flights from St. Louis to Portugal, such as United Airlines, American Airlines, and Air Canada. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Overall

7.4

Crew

8.1

Food

6.6

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
United Airlines
7.4
Good
8,926 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Overall

7.4

Crew

8.1

Food

6.6

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
American Airlines
7.2
Good
10,000 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Overall

7.4

Crew

8.1

Food

6.6

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
Air Canada
7.1
Good
10,000 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Overall

7.4

Crew

8.1

Food

6.6

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
Iberia
7.0
Good
2,955 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Overall

7.4

Crew

8.1

Food

6.6

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
Lufthansa
6.8
Okay
7,424 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Overall

7.4

Crew

8.1

Food

6.6

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Portugal. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to Portugal?

    Lambert-St Louis (STL), located 12.7 mi from the city center, is the airport you fly out of when you book flights from St. Louis to Portugal.

  • How long is the flight from St. Louis to Portugal?

    United Airlines and Delta can get you from St. Louis to Portugal in just under 18h 15m. Your travel time can differ by up to 1h. The distance from St. Louis to Portugal is about 4212 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from St. Louis to Portugal one-way?

    For one-way options, check prices for Air Canada. According to our data, you can fly for as low as $415. Users have also found prices from $655 and $661 on Lufthansa and Austrian Airlines, respectively.

  • What are the most popular routes from St. Louis to Portugal?

    When deciding which route to take from St. Louis to Portugal consider Lambert-St Louis - Lisbon Humberto Delgado, Lambert-St Louis - Porto or Lambert-St Louis - Lajes as they are the most popular.

  • Can I find deals for flights from St. Louis to Portugal that include hotel bookings?

    Yes. In addition to deals on St. Louis to Portugal flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Portugal?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Portugal.

  • Can I find deals for business class flights from St. Louis to Portugal?

    Yes. Cheapflights offers flight deals from St. Louis to Portugal by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to Portugal?

    Currently, January is the cheapest month in which you can book a flight from St. Louis to Portugal (average of $612). Flying from St. Louis to Portugal in June is currently the most expensive (average of $1,126). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Alternative routes for St. Louis to Portugal

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from St. Louis to Portugal

Discover the top 7 airlines that operate flights from St. Louis to Portugal. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 25, 2025.
AirlineCheapestAverageFlexibilityOn-time
IberiaCheapest$566Average$761FlexibilityNo cancel feeOn-time77%
LufthansaCheapest$601Average$1,093FlexibilityNo cancel feeOn-time76%
United AirlinesCheapest$605Average$1,105FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$614Average$1,138FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$667Average$853FlexibilityNo cancel feeOn-time70%
DeltaCheapest$680Average$884FlexibilityNo cancel feeOn-timeN/A
Air CanadaCheapest$823Average$1,106FlexibilityNo cancel feeOn-time67%

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