The present disclosure relates to a steering control apparatus and method, the apparatus comprising: a reception unit which receives an ignition-off signal and an ignition-on signal, and which receives relative steering angle information received from a relative steering angle sensor for measuring only the relative angle of a steering wheel; a calculation unit which calculates section information by using the relative steering angle information, and which calculates absolute steering angle information on the basis of the relative steering angle information and the section information; and a control unit which determines, when the ignition-off signal is received, whether absolute steering angle calculation conditions enabling calculation of the absolute steering angle information are satisfied even after the ignition is off, and which generates an ignition-off control signal according to the determination result.