$126 Cheap American Airlines flights St. Louis (STL) to Harrisburg (MDT)

Make use of the "Price (lowest to highest)" filter on Expedia to search for cheap American Airlines return flights from $249 from STL to MDT. Affordable one-way fares from $126 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.

To find cheap American Airlines fares from Lambert-St. Louis Intl. Airport (STL) to Harrisburg Intl. Airport (MDT), 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 influence the price 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 flight 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.

Filter your results by "Early Morning" and "Morning" to browse the earliest departures from STL to MDT. Setting off early means you're 20% less likely to experience 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.