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Cheap flights from St. Louis to Portugal from $443

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 6/4. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from St. Louis to Portugal

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
7:30 am - 9:45 am
STL
-
OPO
20h 15m
1 stop
United Airlines Logo
12:45 pm - 4:26 pm
OPO
-
STL
33h 41m
2 stops
$829United Airlines
Sun, Oct 4 - Wed, Oct 21
United Airlines Logo
6:15 am - 9:45 am
STL
-
OPO
21h 30m
2 stops
United Airlines Logo
12:45 pm - 9:24 pm
OPO
-
STL
38h 39m
2 stops
$833United Airlines
Sun, Oct 4 - Wed, Oct 21
United Airlines Logo
7:30 am - 8:10 am
STL
-
LIS
19h 40m
1 stop
United Airlines Logo
5:00 am - 10:09 pm
LIS
-
STL
22h 09m
2 stops
$838United Airlines
Sun, Oct 25 - Sun, Nov 1
United Airlines Logo
6:49 pm - 7:00 am
STL
-
OPO
30h 11m
2 stops
United Airlines Logo
12:45 pm - 4:26 pm
OPO
-
STL
33h 41m
2 stops
$838United Airlines
Sun, Oct 4 - Wed, Oct 21
Delta Logo
4:13 pm - 10:25 am
STL
-
OPO
12h 12m
1 stop
Delta Logo
5:00 am - 5:06 pm
OPO
-
STL
18h 06m
2 stops
$841Delta
Sun, Oct 4 - Wed, Oct 21
Delta Logo
9:00 am - 10:25 am
STL
-
OPO
19h 25m
2 stops
Delta Logo
5:00 am - 5:06 pm
OPO
-
STL
18h 06m
2 stops
$846Delta
Sun, Oct 4 - Wed, Oct 21
Multiple Airlines Logo
4:15 pm - 11:00 am
STL
-
LIS
13h 45m
1 stop
Multiple Airlines Logo
3:45 pm - 1:55 pm
LIS
-
STL
28h 10m
1 stop
$849Multiple Airlines
Mon, Oct 26 - Tue, Dec 29
Air Canada Logo
6:45 pm - 9:50 am
STL
-
LIS
34h 05m
2 stops
Air Canada Logo
11:20 am - 2:18 pm
LIS
-
STL
32h 58m
2 stops
$857Air Canada
Mon, Oct 26 - Tue, Dec 29
Multiple Airlines Logo
2:40 pm - 11:05 am
STL
-
LIS
14h 25m
1 stop
Multiple Airlines Logo
5:05 am - 1:25 pm
LIS
-
STL
14h 20m
1 stop
$900Multiple Airlines
Tue, Sep 22 - Tue, Oct 20
Air Canada Logo
12:10 pm - 9:20 am
STL
-
LIS
15h 10m
1 stop
Air Canada Logo
11:25 am - 2:18 pm
LIS
-
STL
32h 53m
2 stops
$903Air Canada
Thu, Oct 15 - Fri, Oct 23

Air France flights from St. Louis to Portugal

Our best Air France deals on St. Louis to Portugal flight tickets
Air France
Sep 7
STL5:30 pmLambert-St Louis
15h 25m
2 stops
LIS2:55 pmLisbon Humberto Delgado
Sep 14
LIS5:35 amLisbon Humberto Delgado
16h 22m
2 stops
STL3:57 pmLambert-St Louis
$1,033
Air France
Sep 5
STL5:45 pmLambert-St Louis
15h 40m
2 stops
OPO3:25 pmPorto
Sep 13
OPO12:25 pmPorto
34h 30m
1 stop
STL4:55 pmLambert-St Louis
$1,059

Air Canada flights from St. Louis to Portugal

Our best Air Canada deals on St. Louis to Portugal flight tickets
Air Canada
Oct 26
STL6:45 pmLambert-St Louis
34h 05m
2 stops
LIS9:50 amLisbon Humberto Delgado
Dec 29
LIS11:20 amLisbon Humberto Delgado
32h 58m
2 stops
STL2:18 pmLambert-St Louis
$857
Air Canada
Oct 15
STL12:10 pmLambert-St Louis
15h 10m
1 stop
LIS9:20 amLisbon Humberto Delgado
Oct 23
LIS11:25 amLisbon Humberto Delgado
32h 53m
2 stops
STL2:18 pmLambert-St Louis
$903
Air Canada
Oct 15
STL6:40 amLambert-St Louis
20h 40m
2 stops
LIS9:20 amLisbon Humberto Delgado
Oct 23
LIS11:25 amLisbon Humberto Delgado
34h 13m
2 stops
STL3:38 pmLambert-St Louis
$908

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 May 1, 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. 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-4:26 pm

2 stops33h 41m

$829

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 10/4

6:15 am-9:45 am

2 stops21h 30m

Porto

Wed 10/21

12:45 pm-9:24 pm

2 stops38h 39m

$833

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Sun 10/25

7:30 am-8:10 am

1 stop19h 40m

Lisbon Humberto Delgado

Sun 11/1

5:00 am-10:09 pm

2 stops22h 09m

$838

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 10/4

6:49 pm-7:00 am

2 stops30h 11m

Porto

Wed 10/21

12:45 pm-4:26 pm

2 stops33h 41m

$838

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 10/4

4:13 pm-10:25 am

1 stop12h 12m

Porto

Wed 10/21

5:00 am-5:06 pm

2 stops18h 06m

$841

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 10/4

9:00 am-10:25 am

2 stops19h 25m

Porto

Wed 10/21

5:00 am-5:06 pm

2 stops18h 06m

$846

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Mon 10/26

4:15 pm-11:00 am

1 stop13h 45m

Lisbon Humberto Delgado

Tue 12/29

3:45 pm-1:55 pm

1 stop28h 10m

$849

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Mon 10/26

6:45 pm-9:50 am

2 stops34h 05m

Lisbon Humberto Delgado

Tue 12/29

11:20 am-2:18 pm

2 stops32h 58m

$857
Quickest round-trip

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Tue 9/22

2:40 pm-11:05 am

1 stop14h 25m

Lisbon Humberto Delgado

Tue 10/20

5:05 am-1:25 pm

1 stop14h 20m

$900

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Thu 10/15

12:10 pm-9:20 am

1 stop15h 10m

Lisbon Humberto Delgado

Fri 10/23

11:25 am-2:18 pm

2 stops32h 53m

$903

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 March. Flight prices, which tend to average around $458, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of March, then book flights to Portugal from St. Louis during February instead. Flights to Portugal in February, while not as cheap as those in March, still average around $460.

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

You are more likely to see cheaper flights to Portugal from St. Louis when booking week ahead of your departure date. In general, you can expect to find flights to Portugal for around $1,040 when searching week 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 $719 on momondo.

Can stopping save me money on St. Louis to Portugal flights?

You could potentially save up to 7% on your flight if you consider stops on a St. Louis to Portugal flight.

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

12h 45m

Direct flights

None
The fastest flight from St. Louis to Portugal takes 12h 45m
There are no direct flights from St. Louis to Portugal. There are no popular flight routes from St. Louis to Portugal.
Search flight deals

Frequently asked questions about flying from St. Louis to Portugal

  • 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
LufthansaPriceFrom $493Free CancellationRating
6.8
7,964 reviews
Search Lufthansa flights
American AirlinesPriceFrom $505Free CancellationRating
7.1
11,676 reviews
Search American Airlines flights
DeltaPriceFrom $558Free CancellationRating
7.9
8,464 reviews
Search Delta flights
IberiaPriceFrom $571Free CancellationRating
7.0
3,205 reviews
Search Iberia flights
British AirwaysPriceFrom $574Free CancellationRating
6.7
7,937 reviews
Search British Airways flights
United AirlinesPriceFrom $617Free CancellationRating
7.4
9,678 reviews
Search United Airlines flights
Air CanadaPriceFrom $675Free CancellationRating
7.1
10,988 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.

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Find better results for your trip to Portugal

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