An information processing device and an information processing method that prevent unnecessary warning are provided. An information processing device includes a host vehicle information acquisition part configured to acquire host vehicle information on a host vehicle, a setting part configured to set an allowable range for a driver's sight of the host vehicle based on the host vehicle information, a driver information acquisition part configured to acquire driver information on the driver, a determination part (inattentive driving determination part) configured to determine whether or not the driver is looking at the allowable range based on the allowable range and the driver information, and an output part (sound output part, vibration part, display part) configured to output a predetermined notification based on the determination of the determination part (inattentive driving determination part).