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Cheap flights from Portland to St. Louis from $128

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Portland to St. Louis departing on 11/4. 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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Cheap round-trip flights

Frontier Logo
6:05 am - 9:07 amPDX-STL
25h 02m1 stop
Frontier Logo
7:52 pm - 10:39 pmSTL-PDX
28h 47m1 stop
$244Frontier
Find Deal
mié., oct. 1 - mar., oct. 7
Frontier Logo
7:01 pm - 9:11 amPDX-STL
12h 10m1 stop
Frontier Logo
7:29 pm - 12:16 amSTL-PDX
6h 47m1 stop
$273Frontier
Find Deal
mar., jul. 15 - lun., ago. 11
American Airlines Logo
3:22 pm - 12:16 amPDX-STL
6h 54m1 stop
American Airlines Logo
1:42 pm - 11:20 pmSTL-PDX
11h 38m1 stop
$282American Airlines
Find Deal
mié., ago. 13 - mié., ago. 20
Delta Logo
12:40 am - 8:34 amPDX-STL
5h 54m1 stop
Delta Logo
5:37 pm - 11:18 pmSTL-PDX
7h 41m1 stop
$297Delta
Find Deal
jue., jul. 10 - lun., jul. 21
Delta Logo
12:40 am - 8:44 amPDX-STL
6h 04m1 stop
Delta Logo
7:30 am - 5:06 pmSTL-PDX
11h 36m2 stops
$301Delta
Find Deal
vie., sep. 12 - mar., sep. 16
United Airlines Logo
5:00 am - 3:44 pmPDX-STL
8h 44m2 stops
United Airlines Logo
5:15 am - 9:28 amSTL-PDX
6h 13m1 stop
$302United Airlines
Find Deal
sáb., ago. 23 - dom., ago. 31
Southwest Logo
5:50 am - 3:00 pmPDX-STL
7h 10m1 stop
Southwest Logo
2:50 pm - 8:00 pmSTL-PDX
7h 10m1 stop
$307Southwest
Find Deal
vie., jul. 11 - vie., jul. 18
Southwest Logo
7:00 am - 5:40 pmPDX-STL
8h 40m2 stops
Southwest Logo
5:25 am - 10:00 amSTL-PDX
6h 35m1 stop
$312Southwest
Find Deal
mié., ago. 27 - jue., sep. 11
American Airlines Logo
12:59 am - 9:18 amPDX-STL
6h 19m1 stop
American Airlines Logo
5:30 am - 12:53 pmSTL-PDX
9h 23m1 stop
$369American Airlines
Find Deal
jue., jul. 31 - dom., ago. 3
United Airlines Logo
7:37 am - 4:45 pmPDX-STL
7h 08m1 stop
United Airlines Logo
8:00 am - 3:14 pmSTL-PDX
9h 14m1 stop
$387United Airlines
Find Deal
vie., jul. 11 - vie., jul. 18

Frontier flights from Portland to St. Louis

Our best Frontier deals on Portland to St. Louis flight tickets
Frontier
Oct 1
PDX6:05 amPortland
25h 02m
1 stop
STL9:07 amLambert-St Louis
Oct 7
STL7:52 pmLambert-St Louis
28h 47m
1 stop
PDX10:39 pmPortland
Frontier
Jul 15
PDX7:01 pmPortland
12h 10m
1 stop
STL9:11 amLambert-St Louis
Aug 11
STL7:29 pmLambert-St Louis
6h 47m
1 stop
PDX12:16 amPortland
Frontier
Aug 25
PDX6:27 amPortland
24h 44m
1 stop
STL9:11 amLambert-St Louis
Aug 28
STL7:54 pmLambert-St Louis
6h 21m
1 stop
PDX12:15 amPortland

American Airlines flights from Portland to St. Louis

Our best American Airlines deals on Portland to St. Louis flight tickets
American Airlines
Aug 13
PDX3:22 pmPortland
6h 54m
1 stop
STL12:16 amLambert-St Louis
Aug 20
STL1:42 pmLambert-St Louis
11h 38m
1 stop
PDX11:20 pmPortland
American Airlines
Jul 31
PDX12:59 amPortland
6h 19m
1 stop
STL9:18 amLambert-St Louis
Aug 3
STL5:30 amLambert-St Louis
9h 23m
1 stop
PDX12:53 pmPortland
American Airlines
Jul 10
PDX12:59 amPortland
6h 19m
1 stop
STL9:18 amLambert-St Louis
Jul 21
STL6:10 pmLambert-St Louis
7h 12m
1 stop
PDX11:22 pmPortland

See travel insights to St. Louis from

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

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 St. Louis?

In general, January is the cheapest month to fly from Portland to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $280. The month of September is another great option to travel to St. Louis, with average flight prices from Portland averaging around $316.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Friday when prices can be found for as low as $366. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $572. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Portland in the evening is the least expensive time of day to depart. momondo users have found prices as low as $288 when looking at flights departing in the evening. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $680 per ticket.

What is the cheapest Portland to Lambert-St Louis flight route?

Fly from Portland to Lambert-St Louis for the best Portland - Lambert-St Louis flight prices

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

You are more likely to see cheaper flights to St. Louis from Portland when booking 25 weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $383 when searching 25 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Portland for as low as $260 on momondo.

What cabin class options are available on Portland to Lambert-St Louis flights?

There are 1 cabin classes available to choose from on Portland to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Portland to St. Louis flight prices changed over time?

As of June 2025, prices for Portland to St. Louis flights are approximately 0% more expensive when compared to flights at the same time last year.

When to book flights from Portland to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Portland to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Portland to St. Louis (PDX to STL) flight deals and tips

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

Best Price Found

$128

Fastest flight time

3h 40m

Direct flights

Mon and Sun

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Portland in the past 72 hours is $128. The best round-trip flight deal from Portland to St. Louis found on momondo in the last 72 hours is $244.
The fastest flight from Portland to St. Louis takes 3h 40m
Direct flights go from Portland to St. Louis on Monday and Sunday. The only airline offering direct flights is Southwest.
There is 1 airport near St. Louis: Lambert-St Louis (STL)

  • How far is Portland to Lambert-St Louis by plane?

    A flight from Portland to Lambert-St Louis will travel around 1718.1 mi. A reasonable flight in good conditions will take 3h 45m.

  • When did momondo last update prices for flights from Portland Airport to Lambert-St Louis Airport?

    Prices for flights from Portland Airport to Lambert-St Louis Airport are updated daily.

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

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

    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 Portland Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Portland to St. Louis?

  • What is the most popular airline from Portland to St. Louis?


Best airlines flying from Portland to St. Louis

Compare and see reviews for airlines that fly from Portland to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $118Free CancellationRating
5.9
3,295 reviews
Search Frontier flights
American AirlinesPriceFrom $196Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
DeltaPriceFrom $212Free CancellationRating
8.0
7,946 reviews
Search Delta flights
United AirlinesPriceFrom $226Free CancellationRating
7.4
8,790 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $244Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $252Free CancellationRating
8.0
4,287 reviews
Search Southwest flights

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Florissant
Fairview Heights
Maryland Heights
Collinsville
Fenton
Farmington
O'Fallon
Alton
St. Peters
Wentzville
Glencoe
Festus
Clayton
Eureka
Edwardsville
Grafton
Shrewsbury

Why use momondo?

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

It is quick and easy to find Portland to St. Louis 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 St. Louis that suits you.

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

momondo does allow users to show only those flights to St. Louis from Portland which offer a flexible booking policy as well as other useful filters and features.

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

Once you have performed a search for Portland to St. Louis 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 Portland to St. Louis right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of Portland to St. Louis flights. All you need is a valid email address and we will do the rest; it is that quick and easy.


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1 adult
mar. 6/17
mar. 6/24

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