$94 Cheap Frontier Airlines flights St. Louis (STL) to Portland (PDX)

Set the “Price (lowest to highest)” filter on Expedia to look for cheap Frontier Airlines round-trip flights from $208 from STL to PDX. Affordable one-way options from $94 are available as well.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

January is one of the least expensive months to fly to Portland with Frontier Airlines. You could also find great prices on return and one-way fares in December.

For cheap Frontier Airlines fares from Lambert-St. Louis Intl. Airport (STL) to Portland Intl. Airport (PDX), start searching one to three months before your planned departure. Securing domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also impact how much you pay. Sunday is usually the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your trip on a Sunday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC’s global airline sales database.

To figure out if there’s a direct trip from STL to PDX with Frontier Airlines or any other carriers, check the “Nonstop” filter when looking for tickets.

Find Frontier Airlines’s earliest flights from STL to PDX by checking our “Early Morning” and “Morning” filters. Not only will you get to where you’re going sooner, early departures also experience 20% fewer cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.

Frontier Airlines flights from Lambert-St. Louis Intl. Airport (STL) to Portland come in to Portland Intl. Airport (PDX). This is the main gateway to this city.

Journey from STL to PDX with Frontier Airlines and enjoy a range of benefits including a rewarding loyalty program. When you book through Expedia as a Frontier Miles and One Key™ member, you could also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

Depending on the type of ticket you purchased, a fee may apply if you change or cancel your booking more than 24 hours after it has been confirmed. To find flexible fares, select our “Changes included” or “No cancel fee” filter when looking for flights. For more details on canceling or changing your reservation, visit “Trips,” select your flight and tick “Manage Booking.”