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Portugal

$357+ 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 10/14. Fares are subject to change and may not be available on all flights or dates of travel.
STL — LIS
Jun 8 — Jun 151
Mon 6/8
Mon 6/15
1 adult, Economy
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Cheap 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 May 9, 2026.

This United Airlines deal was found by Cheapflights users on 5/8. 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.
Tue 12/16:30 am
STL
-
OPO
1 stop21h 00m
United Airlines
Fri 12/46:00 am
OPO
-
STL
1 stop13h 55m
United Airlines
Deal found 5/8$736
This Gotogate deal was found by Cheapflights users on 5/7. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/264:15 pm
STL
-
LIS
1 stop13h 45m
Multiple Airlines
Wed 11/45:00 am
LIS
-
STL
1 stop14h 55m
Multiple Airlines
Deal found 5/7$758
This KAYAK deal was found by Cheapflights users on 5/8. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/43:42 pm
STL
-
LIS
2 stops18h 23m
Scandinavian Airlines
Tue 11/104:55 pm
LIS
-
STL
2 stops36h 44m
Scandinavian Airlines
Deal found 5/8$770
This United Airlines deal was found by Cheapflights users on 5/7. 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.
Tue 11/36:30 am
STL
-
LIS
2 stops21h 20m
United Airlines
Wed 11/115:00 am
LIS
-
STL
1 stop14h 55m
United Airlines
Deal found 5/7$777
This United Airlines deal was found by Cheapflights users on 5/7. 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.
Mon 11/23:15 pm
STL
-
LIS
2 stops13h 00m
United Airlines
Wed 11/115:00 am
LIS
-
STL
1 stop14h 55m
United Airlines
Deal found 5/7$778
This United Airlines deal was found by Cheapflights users on 5/7. 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.
Wed 11/46:30 am
STL
-
LIS
1 stop19h 40m
United Airlines
Tue 11/1011:20 am
LIS
-
STL
2 stops35h 20m
United Airlines
Deal found 5/7$780
This United Airlines deal was found by Cheapflights users on 5/7. 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.
Sun 11/14:15 pm
STL
-
LIS
1 stop12h 45m
United Airlines
Fri 11/135:00 am
LIS
-
STL
1 stop14h 55m
United Airlines
Deal found 5/7$782
This United Airlines deal was found by Cheapflights users on 5/7. 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.
Wed 11/41:27 pm
STL
-
LIS
2 stops14h 48m
United Airlines
Wed 11/115:00 am
LIS
-
STL
1 stop14h 55m
United Airlines
Deal found 5/7$783
This Air Canada deal was found by Cheapflights users on 5/4. 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.
Mon 12/74:15 pm
STL
-
LIS
1 stop12h 45m
Air Canada
Wed 12/911:20 am
LIS
-
STL
2 stops32h 58m
Air Canada
Deal found 5/4$784
This United Airlines deal was found by Cheapflights users on 5/7. 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.
Sat 10/315:20 pm
STL
-
LIS
1 stop33h 50m
United Airlines
Thu 11/121:00 pm
LIS
-
STL
1 stop32h 30m
United Airlines
Deal found 5/7$787
This United Airlines deal was found by Cheapflights users on 5/8. 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.
Sun 10/47:30 am
STL
-
OPO
1 stop20h 15m
United Airlines
Wed 10/2112:45 pm
OPO
-
STL
2 stops38h 39m
United Airlines
Deal found 5/8$829
This Air Canada deal was found by Cheapflights users on 5/7. 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.
Tue 12/14:15 pm
STL
-
OPO
2 stops20h 15m
Air Canada
Fri 12/46:00 am
OPO
-
STL
2 stops39h 30m
Air Canada
Deal found 5/7$862

Find 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 May 9, 2026.

Most accurate provider

Ovago
3 stars

Most trusted provider

Ovago
3 stars

Round-trip from

$758
(Gotogate)

One-way from

$357
(oojo)

Popular in

December

Cheapest in

April

Average price

$978
Provider with most accurate pricing for Lambert-St Louis-Lisbon Humberto Delgado flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Lisbon Humberto Delgado flights.
Search Deals
From Lambert-St Louis to Portugal
Search Deals
One-way flight from Lambert-St Louis to Portugal
Search Deals
Highest demand for flights based on searches. 22% potential increase in price ($306 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 16% potential price decrease ($148 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
Search Deals

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 May 9, 2026.
Use the filters below to find and compare flights from St. Louis to Portugal that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 11/4

6:30 am-8:10 am

1 stop19h 40m

Lisbon Humberto Delgado

Tue 11/10

11:20 am-4:40 pm

2 stops35h 20m

$780

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 10/4

7:30 am-9:45 am

1 stop20h 15m

Porto

Wed 10/21

12:45 pm-9:24 pm

2 stops38h 39m

$829

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Tue 11/3

5:20 pm-8:10 am

1 stop32h 50m

Lisbon Humberto Delgado

Mon 11/9

1:00 pm-3:30 pm

1 stop32h 30m

$837

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Thu 10/15

6:40 am-9:20 am

2 stops20h 40m

Lisbon Humberto Delgado

Fri 10/23

11:25 am-11:03 am

2 stops29h 38m

$907

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 9/16

7:01 am-9:20 am

2 stops20h 19m

Lisbon Humberto Delgado

Fri 9/25

5:05 am-3:38 pm

2 stops16h 33m

$964

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Mon 7/27

6:01 am-8:20 am

1 stop20h 19m

Lisbon Humberto Delgado

Wed 8/5

10:25 am-11:44 pm

1 stop19h 19m

$970

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Sun 7/26

12:10 pm-9:20 am

1 stop15h 10m

Lisbon Humberto Delgado

Fri 8/7

1:00 pm-8:07 pm

1 stop13h 07m

$975
Quickest round-trip

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 8/31

12:10 pm-7:00 am

1 stop12h 50m

Porto

Sat 9/12

9:00 am-3:47 pm

1 stop12h 47m

$976

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 9/5

5:59 pm-6:55 am

2 stops30h 56m

Porto

Sun 9/13

9:00 am-11:37 pm

1 stop20h 37m

$981

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sat 9/5

4:52 pm-6:55 am

1 stop32h 03m

Porto

Sat 9/26

12:20 pm-4:26 pm

2 stops34h 06m

$992

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/4

Showing 1-10 of 30 resultsSorted by cheapest first
1
2
3

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

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

Booking 39 days in advance of your planned departure date is, on average, the best time to get cheap flights from St. Louis to Portugal. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, March is the cheapest month in which you can book a flight from St. Louis to Portugal (average of $458). Flying from St. Louis to Portugal in June is currently the most expensive (average of $791). 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.

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 May 9, 2026.
Read through reviews of airlines operating flights from St. Louis to Portugal, such as Delta,United Airlines, andAmerican Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,460 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Delta
7.9
Good
8,460 reviews
Delta
7.9
Good
8,460 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
United Airlines
7.4
Good
9,694 reviews
Delta
7.9
Good
8,460 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
American Airlines
7.1
Good
11,673 reviews
Delta
7.9
Good
8,460 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Air Canada
7.1
Good
11,008 reviews
Delta
7.9
Good
8,460 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Lufthansa
6.8
Okay
7,984 reviews
Delta
7.9
Good
8,460 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional

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 can get you from St. Louis to Portugal in just under 14h 25m. Your travel time can differ by up to . The distance from St. Louis to Portugal is about 4212 mi.

  • 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, March is the cheapest month in which you can book a flight from St. Louis to Portugal (average of $458). Flying from St. Louis to Portugal in June is currently the most expensive (average of $791). 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.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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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 May 9, 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$493Average$766FlexibilityNo cancel feeOn-time76%
American AirlinesCheapest$505Average$1,075FlexibilityNo cancel feeOn-time71%
DeltaCheapest$558Average$609FlexibilityNo cancel feeOn-timeN/A
IberiaCheapest$571Average$754FlexibilityNo cancel feeOn-time77%
British AirwaysCheapest$574Average$686FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$617Average$1,052FlexibilityNo cancel feeOn-time69%
Air CanadaCheapest$675Average$1,072FlexibilityNo cancel feeOn-time67%

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