A motor drive control device, which drives a motor including a plurality of phase coils and a rotor, includes: a motor driver, which outputs a drive signal to the phase coils on a drive control signal; one position sensor, which is provided in a position where a timing of at least one of a rising edge and a falling edge of a rotor position signal is near a zero cross timing of a phase signal of any phase coil; and a controller that: generates the drive control signal based on the phase signal in a case where a rotational speed of the motor is less than a predetermined rotational speed; and generates the drive control signal based on the rotor position signal output from the one position sensor in a case where the rotational speed is equal to or more than the predetermined rotational speed.