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Cheap flights from St. Louis to Portugal from $255

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Portugal departing on 3/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Cheap round-trip flights

Enter your travel dates to find the best prices.
Lufthansa Logo
3:50 pm - 2:45 pmSTL-OPO
16h 55m1 stop
Lufthansa Logo
6:00 am - 10:58 pmOPO-STL
22h 58m2 stops
$440Lufthansa
Find Deal
Fri, Jan 9 - Sun, Jan 25
Lufthansa Logo
3:50 pm - 2:45 pmSTL-OPO
16h 55m1 stop
Lufthansa Logo
6:00 am - 1:55 pmOPO-STL
13h 55m1 stop
$450Lufthansa
Find Deal
Fri, Jan 9 - Sun, Jan 25
Multiple Airlines Logo
2:54 pm - 12:10 pmSTL-LIS
15h 16m2 stops
Multiple Airlines Logo
8:20 am - 6:14 pmLIS-STL
15h 54m2 stops
$451Multiple Airlines
Find Deal
Wed, Jan 21 - Fri, Jan 30
Iberia Logo
9:33 am - 8:55 amSTL-LIS
17h 22m1 stop
Iberia Logo
8:20 am - 6:14 pmLIS-STL
15h 54m2 stops
$454Iberia
Find Deal
Wed, Jan 21 - Fri, Jan 30
Iberia Logo
9:33 am - 9:05 amSTL-LIS
17h 32m1 stop
Iberia Logo
11:05 am - 10:44 pmLIS-STL
17h 39m1 stop
$470Iberia
Find Deal
Thu, Jan 8 - Wed, Jan 21
United Airlines Logo
8:21 am - 9:20 amSTL-LIS
18h 59m2 stops
United Airlines Logo
5:00 am - 1:55 pmLIS-STL
14h 55m1 stop
$482United Airlines
Find Deal
Tue, Feb 24 - Wed, Mar 4
Delta Logo
6:05 am - 10:30 amSTL-OPO
22h 25m2 stops
Delta Logo
11:25 am - 3:52 pmOPO-STL
34h 27m2 stops
$482Delta
Find Deal
Mon, Dec 8 - Mon, Dec 15
United Airlines Logo
8:45 am - 9:20 amSTL-LIS
18h 35m2 stops
United Airlines Logo
11:20 am - 2:30 pmLIS-STL
33h 10m2 stops
$483United Airlines
Find Deal
Thu, Jan 8 - Thu, Jan 15
Delta Logo
6:05 am - 10:30 amSTL-OPO
22h 25m2 stops
Delta Logo
11:25 am - 3:52 pmOPO-STL
34h 27m2 stops
$483Delta
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Mon, Dec 8 - Mon, Dec 15
Air Canada Logo
4:05 pm - 9:20 amSTL-LIS
35h 15m2 stops
Air Canada Logo
11:20 am - 10:59 pmLIS-STL
41h 39m2 stops
$484Air Canada
Find Deal
Mon, Feb 23 - Tue, Mar 3

United Airlines flights from St. Louis to Portugal

Our best United Airlines deals on St. Louis to Portugal flight tickets
United Airlines
Feb 24
STL8:21 amLambert-St Louis
18h 59m
2 stops
LIS9:20 amLisbon Humberto Delgado
Mar 4
LIS5:00 amLisbon Humberto Delgado
14h 55m
1 stop
STL1:55 pmLambert-St Louis
$482
Find similar
United Airlines
Jan 8
STL8:45 amLambert-St Louis
18h 35m
2 stops
LIS9:20 amLisbon Humberto Delgado
Jan 15
LIS11:20 amLisbon Humberto Delgado
33h 10m
2 stops
STL2:30 pmLambert-St Louis
$483
Find similar
United Airlines
Feb 20
STL7:41 amLambert-St Louis
20h 34m
2 stops
LIS10:15 amLisbon Humberto Delgado
Mar 4
LIS5:00 amLisbon Humberto Delgado
14h 55m
1 stop
STL1:55 pmLambert-St Louis
$487
Find similar

Air Canada flights from St. Louis to Portugal

Our best Air Canada deals on St. Louis to Portugal flight tickets
Air Canada
Feb 23
STL4:05 pmLambert-St Louis
11h 15m
1 stop
LIS9:20 amLisbon Humberto Delgado
Mar 3
LIS11:20 amLisbon Humberto Delgado
40h 40m
2 stops
STL10:00 pmLambert-St Louis
$484
Find similar
Air Canada
Dec 3
STL4:05 pmLambert-St Louis
10h 50m
1 stop
LIS8:55 amLisbon Humberto Delgado
Dec 12
LIS11:20 amLisbon Humberto Delgado
34h 09m
1 stop
STL3:29 pmLambert-St Louis
$529
Find similar
Air Canada
Dec 3
STL4:05 pmLambert-St Louis
10h 50m
1 stop
LIS8:55 amLisbon Humberto Delgado
Dec 17
LIS11:00 amLisbon Humberto Delgado
34h 29m
1 stop
STL3:29 pmLambert-St Louis
$530
Find similar

momondo 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, momondo users made 832,500 searches. Data last updated November 26, 2025.
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

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 1/9

3:50 pm-2:45 pm

1 stop16h 55m

Porto

Sun 1/25

6:00 am-10:58 pm

2 stops22h 58m

$440

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 1/9

3:50 pm-2:45 pm

1 stop16h 55m

Porto

Sun 1/25

6:00 am-1:55 pm

1 stop13h 55m

$450

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 1/21

2:54 pm-12:10 pm

2 stops15h 16m

Lisbon Humberto Delgado

Fri 1/30

8:20 am-6:14 pm

2 stops15h 54m

$451

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 1/21

9:33 am-8:55 am

1 stop17h 22m

Lisbon Humberto Delgado

Fri 1/30

8:20 am-6:14 pm

2 stops15h 54m

$454

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Thu 1/8

9:33 am-9:05 am

1 stop17h 32m

Lisbon Humberto Delgado

Wed 1/21

11:05 am-10:44 pm

1 stop17h 39m

$470

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Tue 2/24

8:21 am-9:20 am

2 stops18h 59m

Lisbon Humberto Delgado

Wed 3/4

5:00 am-1:55 pm

1 stop14h 55m

$482

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 12/8

6:05 am-10:30 am

2 stops22h 25m

Porto

Mon 12/15

11:25 am-3:52 pm

2 stops34h 27m

$482

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Thu 1/8

8:45 am-9:20 am

2 stops18h 35m

Lisbon Humberto Delgado

Thu 1/15

11:20 am-2:30 pm

2 stops33h 10m

$483

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 12/8

6:05 am-10:30 am

2 stops22h 25m

Porto

Mon 12/15

11:25 am-3:52 pm

2 stops34h 27m

$483

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Mon 2/23

4:05 pm-9:20 am

2 stops35h 15m

Lisbon Humberto Delgado

Tue 3/3

11:20 am-10:59 pm

2 stops41h 39m

$484

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Portugal from

How to get the cheapest flight ticket from St. Louis to Portugal

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Portugal?

The cheapest month to fly to Portugal from St. Louis is in February. Flight prices, which tend to average around $721, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of February, then book flights to Portugal from St. Louis during January instead. Flights to Portugal in January, while not as cheap as those in February, still average around $738.

What is the cheapest day to depart on your flight to Portugal?

According to our data, Monday is the cheapest day to fly to Portugal from St. Louis. The lowest ticket price found for a Monday departure recently was $894. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. The most expensive day to fly to Portugal is Thursday, with ticket prices averaging around $1,087.

What is the cheapest time of day to depart on your flight to Portugal?

Our most recent data shows that the best time of day to fly to Portugal is at noon. Flights from St. Louis to Portugal during this time can be as low as $884. In the afternoon is when there is more demand to fly to Portugal, so prices are often more expensive at around $1,083 per ticket.

How far in advance should I book a flight to Portugal?

You are more likely to see cheaper flights to Portugal from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Portugal for around $982 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portugal from St. Louis for as low as $840 on momondo.

Cheap St. Louis to Portugal flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Portugal

Fastest flight time

13h 50m

Direct flights

None
The fastest flight from St. Louis to Portugal takes 13h 50m
There are no direct flights from St. Louis to Portugal. There are no popular flight routes from St. Louis to Portugal.
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  • When did momondo last update prices for flights from Lambert-St Louis Airport to Portugal?

    Prices for flights from Lambert-St Louis Airport to Portugal are refreshed on a daily basis.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Portugal?

  • How old do you have to be to fly from Lambert-St Louis Airport to Portugal?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to Portugal.

  • What documentation or ID do you need to fly to Portugal?

    The travel and health documents you'll need for your trip to Portugal may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Portugal. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Best airlines flying from St. Louis to Portugal

Compare and see reviews for airlines that fly from St. Louis to Portugal with momondo
Airline
Rating
Free Cancellation
Price
American AirlinesPriceFrom $544Free CancellationRating
7.2
11,038 reviews
Search American Airlines flights
LufthansaPriceFrom $549Free CancellationRating
6.8
7,594 reviews
Search Lufthansa flights
United AirlinesPriceFrom $606Free CancellationRating
7.4
9,046 reviews
Search United Airlines flights
IberiaPriceFrom $649Free CancellationRating
7.0
3,034 reviews
Search Iberia flights
DeltaPriceFrom $713Free CancellationRating
7.9
7,998 reviews
Search Delta flights
British AirwaysPriceFrom $733Free CancellationRating
6.7
7,539 reviews
Search British Airways flights
Air CanadaPriceFrom $787Free CancellationRating
7.1
10,476 reviews
Search Air Canada flights

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Portugal?

It is quick and easy to find St. Louis to Portugal flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Portugal that suits you.

Can I find flights from St. Louis to Portugal with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for St. Louis to Portugal flights to just show those with flexible booking policies.

How can momondo help me find flights from St. Louis to Portugal?

Once you have performed a search for St. Louis to Portugal flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from St. Louis to Portugal right now. Can momondo alert me if prices change?

If you are not ready to book a flight from St. Louis to Portugal now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Portugal and let you know when they change.

An easier way to manage your Portugal trip

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Find better results for your trip to Portugal

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