$100 Cheap American Airlines flights Atlanta (ATL) to Harlingen (HRL)

Finding cheap one-way American Airlines flights from ATL to HRL from $100 on Expedia is a cinch — just filter by "Price (lowest to highest)." Or check out our budget-friendly return fares from $200 for your next exciting vacation.**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 before your departure to get cheap fares on American Airlines flights from Hartsfield-Jackson Atlanta Intl. Airport (ATL) to Valley Intl. Airport (HRL). 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.* Time it well, 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 departure from ATL to HRL with American Airlines, filter your search 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.