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Portugal

$297+ 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 8/1. Fares are subject to change and may not be available on all flights or dates of travel.
STL — LIS
Jul 24 — Jul 311
Fri 7/24
Fri 7/31
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 June 24, 2026.

This United Airlines deal was found by Cheapflights users on 6/23. 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.
Wed 11/46:00 am
STL
-
LIS
1 stop20h 10m
United Airlines
Tue 11/1012:25 pm
LIS
-
STL
1 stop31h 20m
United Airlines
Deal found 6/23$744
This oojo deal was found by Cheapflights users on 6/19. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/193:30 pm
STL
-
LIS
1 stop14h 15m
Lufthansa
Wed 10/285:00 am
LIS
-
STL
1 stop14h 45m
Lufthansa
Deal found 6/19$747
This Delta deal was found by Cheapflights users on 6/22. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/64:13 pm
STL
-
OPO
1 stop10h 52m
Delta
Tue 12/811:15 am
OPO
-
STL
2 stops18h 24m
Delta
Deal found 6/22$747
This United Airlines deal was found by Cheapflights users on 6/20. 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 12/66:30 am
STL
-
OPO
1 stop21h 00m
United Airlines
Tue 12/812:35 pm
OPO
-
STL
2 stops29h 31m
United Airlines
Deal found 6/20$750
This CheapOair deal was found by Cheapflights users on 6/23. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/1912:10 pm
STL
-
LIS
1 stop15h 10m
Multiple Airlines
Wed 10/285:00 am
LIS
-
STL
1 stop14h 45m
Multiple Airlines
Deal found 6/23$753
This FlightHub deal was found by Cheapflights users on 6/23. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/1912:10 pm
STL
-
LIS
1 stop15h 10m
Air Canada
Wed 10/2811:20 am
LIS
-
STL
2 stops33h 21m
Air Canada
Deal found 6/23$755
This United Airlines deal was found by Cheapflights users on 6/23. 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.
Sat 11/214:56 pm
STL
-
LIS
1 stop33h 14m
United Airlines
Thu 12/31:00 pm
LIS
-
STL
1 stop32h 30m
United Airlines
Deal found 6/23$762
This FlightHub deal was found by Cheapflights users on 6/19. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:00 am
STL
-
LIS
2 stops23h 00m
Multiple Airlines
Tue 11/103:50 pm
LIS
-
STL
2 stops35h 23m
Multiple Airlines
Deal found 6/19$763
This United Airlines deal was found by Cheapflights users on 6/21. 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 11/42:00 pm
STL
-
OPO
1 stop13h 30m
United Airlines
Sat 11/1412:35 pm
OPO
-
STL
2 stops16h 34m
United Airlines
Deal found 6/21$795
This oojo deal was found by Cheapflights users on 6/21. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/41:24 pm
STL
-
OPO
2 stops19h 56m
Lufthansa
Sat 11/146:00 am
OPO
-
STL
2 stops16h 56m
Lufthansa
Deal found 6/21$798
This Air Canada deal was found by Cheapflights users on 6/23. 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.
Mon 8/1012:10 pm
STL
-
OPO
1 stop12h 50m
Air Canada
Thu 8/2011:50 am
OPO
-
STL
2 stops33h 48m
Air Canada
Deal found 6/23$887
This United deal was found by Cheapflights users on 6/21. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/17:30 am
STL
-
OPO
2 stops41h 40m
Multiple Airlines
Wed 10/711:20 am
OPO
-
STL
2 stops32h 57m
Multiple Airlines
Deal found 6/21$891

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 June 24, 2026.

Most accurate provider

Ovago
3 stars

Most trusted provider

Ovago
3 stars

Round-trip from

$747
(Delta)

One-way from

$297
(Kiwi.com)

Popular in

December

Cheapest in

April

Average price

$1,291
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 ($298 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 15% potential price decrease ($146 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 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 June 24, 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
Quickest round-trip

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 12/6

11:51 am-9:05 am

2 stops15h 14m

Porto

Tue 12/8

9:55 am-8:37 pm

2 stops16h 42m

$751

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 12/6

6:30 am-9:30 am

1 stop21h 00m

Porto

Tue 12/8

12:35 pm-7:40 pm

1 stop13h 05m

$754

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 8/10

7:20 am-7:00 am

2 stops17h 40m

Porto

Thu 8/20

6:00 am-10:27 pm

2 stops22h 27m

$903

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 8/12

3:39 pm-3:25 pm

2 stops17h 46m

Porto

Thu 8/20

5:00 am-11:26 pm

2 stops24h 26m

$904

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Sun 8/9

12:10 pm-9:20 am

1 stop15h 10m

Lisbon Humberto Delgado

Wed 8/19

6:45 am-10:00 pm

2 stops21h 15m

$947

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Mon 7/20

1:13 pm-10:30 am

2 stops15h 17m

Lisbon Humberto Delgado

Mon 7/27

7:25 am-1:25 pm

1 stop36h 00m

$982

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Sat 9/5

6:54 pm-9:20 am

2 stops32h 26m

Lisbon Humberto Delgado

Sun 9/13

5:05 am-1:25 pm

1 stop14h 20m

$1,019

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Sat 9/5

4:50 pm-8:20 am

1 stop33h 30m

Lisbon Humberto Delgado

Sat 9/26

1:00 pm-2:00 pm

1 stop31h 00m

$1,023

St. LouisLajes

STL - TER

STLTER

Lambert-St Louis

Fri 11/6

4:15 pm-11:00 am

2 stops37h 45m

Lajes

Tue 11/10

11:50 am-3:30 pm

2 stops56h 40m

$1,443

St. LouisLajes

STL - TER

STLTER

Lambert-St Louis

Tue 8/4

12:23 pm-12:50 pm

2 stops19h 27m

Lajes

Tue 8/11

7:05 am-7:11 pm

2 stops17h 06m

$4,957

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/23

Showing 1-10 of 21 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

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.

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

Booking 71 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.

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 June 24, 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
7.8
Good
8,433 reviews

Boarding

8.1

Entertainment

7.8

Comfort

7.8

Crew

8.5

Overall

7.8

Food

7.2

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
7.8
Good
8,433 reviews
Delta
7.8
Good
8,433 reviews

Boarding

8.1

Entertainment

7.8

Comfort

7.8

Crew

8.5

Overall

7.8

Food

7.2

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
9,884 reviews
Delta
7.8
Good
8,433 reviews

Boarding

8.1

Entertainment

7.8

Comfort

7.8

Crew

8.5

Overall

7.8

Food

7.2

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
11,752 reviews
Delta
7.8
Good
8,433 reviews

Boarding

8.1

Entertainment

7.8

Comfort

7.8

Crew

8.5

Overall

7.8

Food

7.2

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
11,251 reviews
Delta
7.8
Good
8,433 reviews

Boarding

8.1

Entertainment

7.8

Comfort

7.8

Crew

8.5

Overall

7.8

Food

7.2

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
8,092 reviews
Delta
7.8
Good
8,433 reviews

Boarding

8.1

Entertainment

7.8

Comfort

7.8

Crew

8.5

Overall

7.8

Food

7.2

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?

    KLM, United Airlines, and Air Canada can get you from St. Louis to Portugal in just under 15h 14m. Your travel time can differ by up to 22h 31m. The distance from St. Louis to Portugal is about 4154 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 Lufthansa. According to our data, you can fly for as low as $342. Users have also found prices from $365 and $382 on United Airlines and Air Canada, 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, 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 8 airlines flying from St. Louis to Portugal

Discover the top 8 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 June 24, 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$493Average$812FlexibilityNo cancel feeOn-time76%
American AirlinesCheapest$505Average$1,075FlexibilityNo cancel feeOn-time71%
KLMCheapest$513Average$1,265FlexibilityNo cancel feeOn-time75%
DeltaCheapest$558Average$609FlexibilityNo cancel feeOn-timeN/A
IberiaCheapest$571Average$745FlexibilityNo cancel feeOn-time77%
British AirwaysCheapest$574Average$686FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$617Average$1,162FlexibilityNo cancel feeOn-time69%
Air CanadaCheapest$649Average$1,067FlexibilityNo cancel feeOn-time67%

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