Delta Airlines offers a Risk-Free Cancellation policy for all tickets purchased directly with the airline, including both refundable and non-refundable fares. Under this policy, you can cancel your flight without penalty and receive a full refund if you cancel your flight within 24 hours of booking.

If you need to cancel your Delta flight after the 24-hour window has passed, the airline may charge a cancellation fee depending on the fare type and destination. The fee amount can vary, so it's important to check directly with Delta for their specific cancellation policy and fee schedule.

Delta also offers a flexible travel waiver policy for certain circumstances, such as severe weather or unexpected personal events. This Delta Cancellation Policy may allow you to change or cancel your flight without penalty, even if it's within 24 hours of departure. However, the specifics of the waiver policy can vary depending on the situation, so it's important to check with Delta directly if you think you may qualify for a waiver.

In summary, you can cancel a Delta flight without penalty if you cancel within 24 hours of booking. After that, the airline may charge a cancellation fee depending on the fare type and destination. Delta also offers a flexible travel waiver policy for certain circumstances, which may allow you to cancel or change your flight without penalty.