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Cheap flights from St. Louis to Portugal from $304

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 9/21. 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

United Airlines Logo
8:15 am - 10:15 amSTL-LIS
20h 00m1 stop
United Airlines Logo
10:55 am - 10:52 amLIS-STL
29h 57m2 stops
$590United Airlines
Find Deal
Wed, Dec 31 - Thu, Jan 15
United Airlines Logo
9:55 am - 8:10 amSTL-LIS
16h 15m2 stops
United Airlines Logo
5:00 am - 1:55 pmLIS-STL
14h 55m1 stop
$591United Airlines
Find Deal
Wed, Dec 31 - Fri, Jan 16
Iberia Logo
9:47 am - 4:00 pmSTL-OPO
24h 13m2 stops
Iberia Logo
8:20 am - 7:27 pmOPO-STL
17h 07m2 stops
$601Iberia
Find Deal
Mon, Nov 10 - Fri, Nov 21
Air Canada Logo
8:05 am - 9:20 amSTL-LIS
19h 15m2 stops
Air Canada Logo
11:20 am - 3:29 pmLIS-STL
34h 09m1 stop
$605Air Canada
Find Deal
Tue, Jan 6 - Fri, Jan 16
Air Canada Logo
6:35 pm - 9:20 amSTL-LIS
32h 45m2 stops
Air Canada Logo
10:55 am - 10:52 amLIS-STL
29h 57m2 stops
$606Air Canada
Find Deal
Mon, Jan 5 - Thu, Jan 15
American Airlines Logo
9:35 am - 7:35 amSTL-OPO
16h 00m2 stops
American Airlines Logo
8:20 am - 8:23 pmOPO-STL
18h 03m2 stops
$608American Airlines
Find Deal
Tue, Oct 14 - Wed, Nov 5
Iberia Logo
9:47 am - 4:00 pmSTL-OPO
24h 13m2 stops
Iberia Logo
4:40 pm - 7:27 pmOPO-STL
32h 47m2 stops
$612Iberia
Find Deal
Mon, Nov 10 - Wed, Nov 19
Lufthansa Logo
12:25 pm - 10:25 amSTL-OPO
16h 00m2 stops
Lufthansa Logo
6:00 am - 1:55 pmOPO-STL
13h 55m1 stop
$640Lufthansa
Find Deal
Tue, Oct 14 - Wed, Nov 5
Lufthansa Logo
3:50 pm - 11:40 amSTL-OPO
13h 50m1 stop
Lufthansa Logo
4:15 pm - 1:55 pmOPO-STL
27h 40m1 stop
$641Lufthansa
Find Deal
Wed, Nov 12 - Tue, Nov 18
American Airlines Logo
9:46 am - 7:35 amSTL-OPO
15h 49m2 stops
American Airlines Logo
8:15 am - 7:23 pmOPO-STL
17h 08m2 stops
$768American Airlines
Find Deal
Tue, Sep 30 - Wed, Oct 15

United Airlines flights from St. Louis to Portugal

Our best United Airlines deals on St. Louis to Portugal flight tickets
United Airlines
Dec 31
STL8:15 amLambert-St Louis
20h 00m
1 stop
LIS10:15 amLisbon Humberto Delgado
Jan 15
LIS10:55 amLisbon Humberto Delgado
29h 57m
2 stops
STL10:52 amLambert-St Louis
$590
Find similar
United Airlines
Dec 31
STL9:55 amLambert-St Louis
16h 15m
2 stops
LIS8:10 amLisbon Humberto Delgado
Jan 16
LIS5:00 amLisbon Humberto Delgado
14h 55m
1 stop
STL1:55 pmLambert-St Louis
$591
Find similar
United Airlines
Jan 5
STL4:05 pmLambert-St Louis
11h 15m
1 stop
LIS9:20 amLisbon Humberto Delgado
Jan 15
LIS10:55 amLisbon Humberto Delgado
29h 57m
2 stops
STL10:52 amLambert-St Louis
$592
Find similar

Delta flights from St. Louis to Portugal

Our best Delta deals on St. Louis to Portugal flight tickets
Delta
Jan 6
STL12:00 pmLambert-St Louis
14h 00m
1 stop
LIS8:00 amLisbon Humberto Delgado
Jan 14
LIS10:00 amLisbon Humberto Delgado
16h 57m
1 stop
STL8:57 pmLambert-St Louis
$618
Find similar
Delta
Nov 9
STL11:44 amLambert-St Louis
16h 46m
2 stops
OPO10:30 amPorto
Nov 16
OPO11:25 amPorto
26h 59m
2 stops
STL8:24 amLambert-St Louis
$690
Find similar
Delta
Nov 9
STL11:44 amLambert-St Louis
16h 46m
2 stops
OPO10:30 amPorto
Nov 17
OPO6:30 amPorto
23h 10m
2 stops
STL11:40 pmLambert-St Louis
$695
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 August 28, 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. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 12/31

8:15 am-10:15 am

1 stop20h 00m

Lisbon Humberto Delgado

Thu 1/15

10:55 am-10:52 am

2 stops29h 57m

$590

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 12/31

9:55 am-8:10 am

2 stops16h 15m

Lisbon Humberto Delgado

Fri 1/16

5:00 am-1:55 pm

1 stop14h 55m

$591

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 11/10

9:47 am-4:00 pm

2 stops24h 13m

Porto

Fri 11/21

8:20 am-7:27 pm

2 stops17h 07m

$601

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Tue 1/6

8:05 am-9:20 am

2 stops19h 15m

Lisbon Humberto Delgado

Fri 1/16

11:20 am-3:29 pm

1 stop34h 09m

$605

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Mon 1/5

6:35 pm-9:20 am

2 stops32h 45m

Lisbon Humberto Delgado

Thu 1/15

10:55 am-10:52 am

2 stops29h 57m

$606

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 10/14

9:35 am-7:35 am

2 stops16h 00m

Porto

Wed 11/5

8:20 am-8:23 pm

2 stops18h 03m

$608

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Mon 11/10

9:47 am-4:00 pm

2 stops24h 13m

Porto

Wed 11/19

4:40 pm-7:27 pm

2 stops32h 47m

$612

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 10/14

12:25 pm-10:25 am

2 stops16h 00m

Porto

Wed 11/5

6:00 am-1:55 pm

1 stop13h 55m

$640

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 11/12

3:50 pm-11:40 am

1 stop13h 50m

Porto

Tue 11/18

4:15 pm-1:55 pm

1 stop27h 40m

$641

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 9/30

9:46 am-7:35 am

2 stops15h 49m

Porto

Wed 10/15

8:15 am-7:23 pm

2 stops17h 08m

$768

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 November. Flight prices, which tend to average around $632, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of November, then book flights to Portugal from St. Louis during February instead. Flights to Portugal in February, while not as cheap as those in November, still average around $672.

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 $934 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 $912 on momondo.

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

You could potentially save up to 20% 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

Direct flights

None
There are no direct flights from St. Louis to Portugal. There are no popular flight routes from St. Louis to Portugal.
Search flight deals

  • 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
IberiaPriceFrom $568Free CancellationRating
7.0
2,892 reviews
Search Iberia flights
LufthansaPriceFrom $601Free CancellationRating
6.8
7,368 reviews
Search Lufthansa flights
United AirlinesPriceFrom $603Free CancellationRating
7.4
8,944 reviews
Search United Airlines flights
American AirlinesPriceFrom $614Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
British AirwaysPriceFrom $667Free CancellationRating
6.7
7,316 reviews
Search British Airways flights
DeltaPriceFrom $680Free CancellationRating
7.9
7,977 reviews
Search Delta flights
Air CanadaPriceFrom $819Free CancellationRating
7.1
10,000 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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