$210 Cheap American Airlines flights St. Louis (STL) to Tri-Cities (TRI)

Scoring cheap one-way American Airlines flights from STL to TRI from $210 on Expedia is easy — just filter by "Price (lowest to highest)." Alternatively, check out our affordable round-trip fares from $288 for your next 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.

Start searching one to three months before your departure to find cheap fares on American Airlines flights from Lambert-St. Louis Intl. Airport (STL) to Tri-Cities Regional Airport (TRI). You can save 25% by booking your domestic flight 34 to 86 days in advance compared to last-minute reservations made 6 to 12 days out. You could also cut costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Get your timing spot on, and you can enjoy significant savings on domestic flights.*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 departures from STL to TRI with American Airlines, sort your results by "Early Morning" and "Morning." Choosing an early flight usually means you'll experience 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.