$98 Cheap Flights from Portland (PDX) to St. Louis (STL)

View $98 flight on Mon, Oct 20, 2025Opens in a new window

Popular airlines from Portland International Airport (PDX) to St. Louis Lambert Intl. Airport (STL)

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

Prices were available within the past 7 days and start at $98 for one-way flights and $182 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Tue, Sep 23 - Wed, Oct 8
PDX
Portland
STL
St. Louis
$182 Roundtrip, found 5 days ago
$182
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Tue, Sep 23 from Portland to St. Louis, returning Wed, Oct 8, priced at $182 found 5 days ago
Frontier Airlines
Thu, Sep 25 - Wed, Oct 8
PDX
Portland
STL
St. Louis
$196 Roundtrip, found 5 days ago
$196
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Thu, Sep 25 from Portland to St. Louis, returning Wed, Oct 8, priced at $196 found 5 days ago
Frontier Airlines
Tue, Sep 30 - Fri, Oct 17
PDX
Portland
STL
St. Louis
$204 Roundtrip, found 5 days ago
$204
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Tue, Sep 30 from Portland to St. Louis, returning Fri, Oct 17, priced at $204 found 5 days ago
Frontier Airlines
Thu, Sep 25 - Fri, Oct 17
PDX
Portland
STL
St. Louis
$218 Roundtrip, found 5 days ago
$218
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Thu, Sep 25 from Portland to St. Louis, returning Fri, Oct 17, priced at $218 found 5 days ago
Frontier Airlines
Mon, Oct 20 - Thu, Oct 23
PDX
Portland
STL
St. Louis
$224 Roundtrip, found 2 hours ago
$224
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Mon, Oct 20 from Portland to St. Louis, returning Thu, Oct 23, priced at $224 found 2 hours ago
Frontier Airlines
Mon, Oct 13 - Sat, Oct 18
PDX
Portland
STL
St. Louis
$226 Roundtrip, found 3 days ago
$226
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Mon, Oct 13 from Portland to St. Louis, returning Sat, Oct 18, priced at $226 found 3 days ago
Alaska Airlines
Mon, Oct 27 - Tue, Nov 4
PDX
Portland
STL
St. Louis
$244 Roundtrip, found 1 day ago
$244
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Mon, Oct 27 from Portland to St. Louis, returning Tue, Nov 4, priced at $244 found 1 day ago
United
Sat, Oct 25 - Sat, Nov 1
PDX
Portland
STL
St. Louis
$244 Roundtrip, found 2 hours ago
$244
Roundtrip
found 2 hours ago
Select United flight, departing Sat, Oct 25 from Portland to St. Louis, returning Sat, Nov 1, priced at $244 found 2 hours ago
Southwest Airlines
Thu, Nov 13 - Sat, Nov 15
PDX
Portland
STL
St. Louis
$246 Roundtrip, found 5 days ago
$246
Roundtrip
found 5 days ago
Select Southwest Airlines flight, departing Thu, Nov 13 from Portland to St. Louis, returning Sat, Nov 15, priced at $246 found 5 days ago
Delta
Sun, Nov 9 - Mon, Nov 17
PDX
Portland
STL
St. Louis
$248 Roundtrip, found 20 hours ago
$248
Roundtrip
found 20 hours ago
Select Delta flight, departing Sun, Nov 9 from Portland to St. Louis, returning Mon, Nov 17, priced at $248 found 20 hours ago

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

October is typically the cheapest month to fly

From $135 - $348 per traveler.

Frequently asked questions

How much does a flight from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL) cost?
Get a cheap one-way flight from $98 or cheap return flight from $182 from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight deals on this route.
What is the cheapest month to fly from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL)?
The cheapest month to fly from PDX to STL is September, when demand is low. Off-peak months are often when you'll find cheap fares for travel between these airports.
What is the cheapest airline that flies from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL)?
To find the cheapest airline that'll fly you from PDX to STL, use Expedia's filter tool. Tailor your search based on what's important to you, such as preferred carriers and flight duration. You can then sort your results by "Price (lowest to highest)" to discover the cheapest flight right away.
How many flights per day from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL)?
Nonstop flights from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL) aren't available daily, so you'll need to take a flight with a layover. Explore your options with Expedia's filter tool. Enter your dates and click on either "1 Stop" or "2+ Stops."
What day of the week has the most flights from PDX to STL?
Friday is usually the busiest day for flights, while Tuesday tends to be the quietest.* Remember that flight schedules can change depending on a range of factors, including the carrier and season.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What airline has the least delays from PDX to STL?
Consider traveling with Sun Country Airlines if you'd like to go straight from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL) without any delays. This airline has the best track record for punctuality, with an on-time performance of 100%. Want to be notified if anything changes? You can keep an eye on your flight status using the Expedia App.
What is the best time to fly from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL)?
To avoid potential delays on the Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL) route, aim to fly before 3 PM. Departures after this hour have a 22% higher chance of being canceled.**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. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Last-minute bookings from PDX to STL are usually more expensive. To secure the best rates, start searching for flights as early as possible. That said, if you can play around with your travel dates, it's possible to find a cheap ticket right before your trip.
Is it cheaper to book a PDX to STL flight and hotel package?
You'll generally save money by booking a PDX to STL flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's easy to manage it all in one convenient place. Once you've selected your preferred accommodations and flights, consider other add-ons like car rentals, tours and activities.
Can I cancel or change the date of my flight from Portland Intl. Airport (PDX) to Lambert-St. Louis Intl. Airport (STL)?
If you booked your PDX to STL flight within the last 24 hours, you may be able to cancel or modify it without any fees. Depending on the airline and the fare type you purchased, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more information.

Travel information

Travel information

Origin airport
Portland Intl.
Destination airport
Lambert-St. Louis Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$182
Distance
1703 mi

Book with confidence

Book with confidence

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 $98 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.

 

Portland to St. Louis Flights

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Explore a world of travel with Expedia

*Available to One Key members.