$46 Cheap American Airlines flights Chicago (ORD) to St. Louis (STL)

You can discover affordable round-trip American Airlines flights from $91 from ORD to STL by sorting your results from "Price (lowest to highest)" on Expedia. Or search for deals from $46 for a one-way journey.**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.

Begin your search one to three months ahead of your travel date to get cheaper fares on American Airlines flights from O'Hare Intl. Airport (ORD) to Lambert-St. Louis Intl. Airport (STL). You can save 25% by booking your domestic flight 34 to 86 days in advance versus last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Nail your timing, and you can enjoy significant savings on domestic trips.*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.

The earliest American Airlines flight from ORD to STL departs at 9:45AM UTC-6, arriving at 11:17AM UTC-6. If you prefer to jet off later, the last American Airlines flight leaves ORD at 8:45PM UTC-6 and lands at STL at 10:26PM UTC-6. Flying earlier is generally a smart choice as morning and mid-morning flights are 20% less likely to be canceled.**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.