$143 Cheap Flights from Portland (PWM) to St. Louis (STL)

View $143 flight on Thu, Oct 9, 2025Opens in a new window

Popular airlines from Portland Intl. Jetport Airport (PWM) to St. Louis Lambert Intl. Airport (STL)

Cheap Flights from Portland to St. Louis (PWM-STL)

Prices were available within the past 7 days and start at $143 for one-way flights and $279 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Sat, Sep 6 - Tue, Sep 9
PWM
Portland
STL
St. Louis
$279 Roundtrip, found 2 days ago
$279
Roundtrip
found 2 days ago
Select American Airlines flight, departing Sat, Sep 6 from Portland to St. Louis, returning Tue, Sep 9, priced at $279 found 2 days ago
American Airlines
Thu, Sep 25 - Mon, Sep 29
PWM
Portland
STL
St. Louis
$282 Roundtrip, found 3 hours ago
$282
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Thu, Sep 25 from Portland to St. Louis, returning Mon, Sep 29, priced at $282 found 3 hours ago
Delta
Thu, Sep 25 - Mon, Sep 29
PWM
Portland
STL
St. Louis
$285 Roundtrip, found 3 hours ago
$285
Roundtrip
found 3 hours ago
Select Delta flight, departing Thu, Sep 25 from Portland to St. Louis, returning Mon, Sep 29, priced at $285 found 3 hours ago
United
Thu, Sep 25 - Mon, Sep 29
PWM
Portland
STL
St. Louis
$285 Roundtrip, found 3 hours ago
$285
Roundtrip
found 3 hours ago
Select United flight, departing Thu, Sep 25 from Portland to St. Louis, returning Mon, Sep 29, priced at $285 found 3 hours ago
Delta
Wed, Aug 20 - Mon, Sep 1
PWM
Portland
STL
St. Louis
$287 Roundtrip, found 10 hours ago
$287
Roundtrip
found 10 hours ago
Select Delta flight, departing Wed, Aug 20 from Portland to St. Louis, returning Mon, Sep 1, priced at $287 found 10 hours ago
American Airlines
Thu, Sep 25 - Mon, Sep 29
PWM
Portland
STL
St. Louis
$287 Roundtrip, found 3 hours ago
$287
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Thu, Sep 25 from Portland to St. Louis, returning Mon, Sep 29, priced at $287 found 3 hours ago
American Airlines
Wed, Aug 13 - Mon, Aug 25
PWM
Portland
STL
St. Louis
$288 Roundtrip, found 8 hours ago
$288
Roundtrip
found 8 hours ago
Select American Airlines flight, departing Wed, Aug 13 from Portland to St. Louis, returning Mon, Aug 25, priced at $288 found 8 hours ago
American Airlines
Thu, Sep 25 - Mon, Sep 29
PWM
Portland
STL
St. Louis
$290 Roundtrip, found 3 hours ago
$290
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Thu, Sep 25 from Portland to St. Louis, returning Mon, Sep 29, priced at $290 found 3 hours ago
Southwest Airlines
Wed, Oct 22 - Tue, Oct 28
PWM
Portland
STL
St. Louis
$291 Roundtrip, found 5 days ago
$291
Roundtrip
found 5 days ago
Select Southwest Airlines flight, departing Wed, Oct 22 from Portland to St. Louis, returning Tue, Oct 28, priced at $291 found 5 days ago
Frontier Airlines
Sat, Aug 16 - Fri, Aug 22
PWM
Portland
STL
St. Louis
$306 Roundtrip, found 10 hours ago
$306
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Sat, Aug 16 from Portland to St. Louis, returning Fri, Aug 22, priced at $306 found 10 hours ago

Find the cheapest month to fly from Portland (PWM) to St. Louis (STL)

September is typically the cheapest month to fly

From $208 - $492 per traveler.

Graph displaying average flight prices per month

Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $427
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $427
Flights from Portland (PWM) to St. Louis (STL)
Origin airport
Portland Intl. Jetport
Destination airport
Lambert-St. Louis Intl.
Airlines serving
American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$279
Distance
1093 mi

Portland to St. Louis Flights

The cheapest times to fly from Portland to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Portland to St. Louis are during the month of September. You can find some of the cheapest flights from Portland to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Portland to St. Louis

Sunday is one of the best days to book for cheap flights from Portland to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Portland to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Portland to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $143 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Portland to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Portland to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL) cost?
Discover the latest flight deals from PWM to STL by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from PWM to STL?
The cheapest flights from PWM to STL are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from PWM to STL?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from PWM to STL. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL)?
You'll have to take a flight with a layover if you're traveling from Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL). Direct flights don't operate daily on this route. However, just filter your search to include one or more stops to discover the best option for your trip.
What day of the week has the most flights from PWM to STL?
Friday is generally the busiest day for flights, while Tuesday tends to be the quietest.* Keep in mind that flight schedules can vary based on various factors, including the time of year and airline.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL)?
To avoid possible delays on the Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL) route, aim to fly before 3 PM. Later departures have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Holding off until right before your break to book a flight from PWM to STL often results in higher prices. While you may come across some last-minute discounts, they aren't always guaranteed. Be flexible with your itinerary for a better chance of snagging a bargain.
Is it cheaper to book a PWM to STL flight and hotel package?
Compared with arranging hotels and flights separately, booking a PWM to STL flight and hotel package with Expedia could result in significant savings. Better still, having everything in one place will take the hassle out of travel planning. Simply secure your flights and select from our wide range of hotels, then personalize your trip with other add-ons like tours, car rentals and activities.
Can I cancel or change the date of my flight from Portland Intl. Jetport Airport (PWM) to Lambert-St. Louis Intl. Airport (STL)?
In most instances, you can cancel or reschedule your PWM to STL flight. However, there may be additional charges, especially if you made your booking more than 24 hours ago. Check your itinerary for the airline's fees and guidelines on flight changes, or if you'd like more information, go to our Customer Service portal.

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*Available to One Key members.