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Cheap flights from St. Louis to Portugal from $317

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 10/19. 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
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from St. Louis to Portugal

Cheap round-trip flights

Enter your travel dates to find the best prices.
Lufthansa Logo
3:40 pm - 11:45 am
STL
-
OPO
14h 05m
1 stop
Lufthansa Logo
6:00 am - 1:45 pm
OPO
-
STL
13h 45m
1 stop
$737Lufthansa
Wed, Nov 4 - Wed, Nov 11
Lufthansa Logo
1:27 pm - 11:55 pm
STL
-
OPO
28h 28m
2 stops
Lufthansa Logo
6:00 am - 1:45 pm
OPO
-
STL
13h 45m
1 stop
$743Lufthansa
Wed, Nov 4 - Wed, Nov 11
United Airlines Logo
7:30 am - 9:30 am
STL
-
OPO
20h 00m
1 stop
United Airlines Logo
6:00 am - 11:25 pm
OPO
-
STL
23h 25m
2 stops
$745United Airlines
Sun, Dec 6 - Thu, Dec 10
United Airlines Logo
6:15 am - 9:30 am
STL
-
OPO
21h 15m
2 stops
United Airlines Logo
6:00 am - 3:30 pm
OPO
-
STL
39h 30m
2 stops
$748United Airlines
Tue, Dec 1 - Tue, Dec 8
United Airlines Logo
6:15 am - 9:30 am
STL
-
OPO
21h 15m
2 stops
United Airlines Logo
6:00 am - 12:34 am
OPO
-
STL
24h 34m
2 stops
$750United Airlines
Sun, Dec 6 - Thu, Dec 10
United Airlines Logo
6:30 am - 9:30 am
STL
-
OPO
21h 00m
1 stop
United Airlines Logo
12:35 pm - 7:40 pm
OPO
-
STL
13h 05m
1 stop
$754United Airlines
Sun, Dec 6 - Tue, Dec 8
Air Canada Logo
6:40 am - 11:00 am
STL
-
LIS
22h 20m
2 stops
Air Canada Logo
1:00 pm - 2:18 pm
LIS
-
STL
31h 18m
2 stops
$792Air Canada
Wed, Nov 4 - Tue, Nov 10
Delta Logo
9:45 am - 8:00 am
STL
-
LIS
16h 15m
2 stops
Delta Logo
5:00 am - 4:50 pm
LIS
-
STL
17h 50m
2 stops
$793Delta
Wed, Nov 4 - Tue, Nov 10
Multiple Airlines Logo
2:40 pm - 6:50 am
STL
-
OPO
34h 10m
2 stops
Multiple Airlines Logo
7:20 pm - 8:00 pm
OPO
-
STL
30h 40m
2 stops
$850Multiple Airlines
Fri, Oct 16 - Mon, Oct 19
Air Canada Logo
4:15 pm - 11:00 am
STL
-
TER
37h 45m
2 stops
Air Canada Logo
11:50 am - 3:30 pm
TER
-
STL
56h 40m
2 stops
$1,302Air Canada
Fri, Nov 6 - Tue, Nov 10

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Lufthansa flights from St. Louis to Portugal

Our best Lufthansa deals on St. Louis to Portugal flight tickets
Lufthansa
Nov 4
STL3:40 pmLambert-St Louis
14h 05m
1 stop
OPO11:45 amPorto
Nov 11
OPO6:00 amPorto
13h 45m
1 stop
STL1:45 pmLambert-St Louis
$737
Lufthansa
Nov 4
STL1:27 pmLambert-St Louis
28h 28m
2 stops
OPO11:55 pmPorto
Nov 11
OPO6:00 amPorto
13h 45m
1 stop
STL1:45 pmLambert-St Louis
$743
Lufthansa
Nov 4
STL1:27 pmLambert-St Louis
28h 28m
2 stops
OPO11:55 pmPorto
Nov 11
OPO4:10 pmPorto
37h 15m
2 stops
STL11:25 pmLambert-St Louis
$773

United Airlines flights from St. Louis to Portugal

Our best United Airlines deals on St. Louis to Portugal flight tickets
United Airlines
Dec 6
STL7:30 amLambert-St Louis
20h 00m
1 stop
OPO9:30 amPorto
Dec 10
OPO6:00 amPorto
23h 25m
2 stops
STL11:25 pmLambert-St Louis
$745
United Airlines
Dec 1
STL6:15 amLambert-St Louis
21h 15m
2 stops
OPO9:30 amPorto
Dec 8
OPO6:00 amPorto
39h 30m
2 stops
STL3:30 pmLambert-St Louis
$748
United Airlines
Dec 6
STL6:15 amLambert-St Louis
21h 15m
2 stops
OPO9:30 amPorto
Dec 10
OPO6:00 amPorto
24h 34m
2 stops
STL12:34 amLambert-St Louis
$750

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 June 19, 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

Wed 11/4

3:40 pm-11:45 am

1 stop14h 05m

Porto

Wed 11/11

6:00 am-1:45 pm

1 stop13h 45m

$737

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Wed 11/4

1:27 pm-11:55 pm

2 stops28h 28m

Porto

Wed 11/11

6:00 am-1:45 pm

1 stop13h 45m

$743

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 12/6

7:30 am-9:30 am

1 stop20h 00m

Porto

Thu 12/10

6:00 am-11:25 pm

2 stops23h 25m

$745

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Tue 12/1

6:15 am-9:30 am

2 stops21h 15m

Porto

Tue 12/8

6:00 am-3:30 pm

2 stops39h 30m

$748

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Sun 12/6

6:15 am-9:30 am

2 stops21h 15m

Porto

Thu 12/10

6:00 am-12:34 am

2 stops24h 34m

$750

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. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 11/4

6:40 am-11:00 am

2 stops22h 20m

Lisbon Humberto Delgado

Tue 11/10

1:00 pm-2:18 pm

2 stops31h 18m

$792

St. LouisLisbon

STL - LIS

STLLIS

Lambert-St Louis

Wed 11/4

9:45 am-8:00 am

2 stops16h 15m

Lisbon Humberto Delgado

Tue 11/10

5:00 am-4:50 pm

2 stops17h 50m

$793

St. LouisPorto

STL - OPO

STLOPO

Lambert-St Louis

Fri 10/16

2:40 pm-6:50 am

2 stops34h 10m

Porto

Mon 10/19

7:20 pm-8:00 pm

2 stops30h 40m

$850

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

$1,302

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 weeks ahead of your departure date. In general, you can expect to find flights to Portugal for around $1,059 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 $746 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 50m

Direct flights

None
The fastest flight from St. Louis to Portugal takes 12h 50m
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
8,077 reviews
Search Lufthansa flights
American AirlinesPriceFrom $505Free CancellationRating
7.1
11,703 reviews
Search American Airlines flights
KLMPriceFrom $513Free CancellationRating
7.8
1,530 reviews
Search KLM flights
DeltaPriceFrom $558Free CancellationRating
7.8
8,418 reviews
Search Delta flights
IberiaPriceFrom $571Free CancellationRating
7.0
3,238 reviews
Search Iberia flights
British AirwaysPriceFrom $574Free CancellationRating
6.7
8,055 reviews
Search British Airways flights
United AirlinesPriceFrom $617Free CancellationRating
7.4
9,863 reviews
Search United Airlines flights
Air CanadaPriceFrom $674Free CancellationRating
7.1
11,221 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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