American Airlines provides a 24-hour grace period for flight cancellations. You can cancel your flight within 24 hours of booking and receive a full refund, regardless of the ticket type. After 24 hours, refund eligibility depends on whether you have a refundable or non-refundable ticket. Refundable fares can be fully refunded, while non-refundable ones may offer credits. Check your ticket details on the official American Airlines website or contact customer service to manage your cancellation and ensure the best outcome.