$819 Cheap American Airlines flights St. Louis (STL) to Oulu (OUL)

Landing cheap one-way American Airlines flights from STL to OUL from $819 on Expedia is a cinch — just filter by "Price (lowest to highest)." Or check out our budget-friendly round-trip fares from $1,446 for your next exciting getaway.**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.

Getting the best American Airlines deals from STL to OUL often comes down to timing. You can save 17% on international flights when you book 18 to 29 days before takeoff instead of four to five months ahead. To top it off, you can pocket 17% on average by buying your tickets on a Sunday rather than a Friday, which is usually the most expensive day to book.* It's smart to kick off your flight search about one month before you want to travel.*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 find the earliest departure from STL to OUL with American Airlines, filter your results by "Early Morning" and "Morning." Choosing an early flight generally means cancellations are less likely.**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.