Yes, you can cancel your flight with Delta Airlines. To do so, simply log into your account online, click on the "My Trips" tab and select the flight you wish to cancel. Click the "Cancel Flight" button, confirm the cancellation and receive your refund. Or, you can call Delta’s customer service department at 1-800-221-1212. Keep in mind that fees may be attached to the cancellation; be sure to review the airline's policy before canceling your flight.