HYDRAULIC PRESSURE CONTROL DEVICE, BRAKE SYSTEM, AND SADDLE-TYPE VEHICLE

To obtain a hydraulic pressure control device capable of suppressing an increase in complexity around a handlebar as compared with the related art when mounted to a straddle-type vehicle. [0002] The hydraulic pressure control device according to the present invention is mounted to the handlebar of a straddle-type vehicle. The hydraulic pressure control device includes: a master cylinder-integrated base body where an internal flow path as a part of a brake fluid flow path allowing a piston mounting hole provided with a piston of a master cylinder and a wheel cylinder to communicate with each other is formed; a control valve opening and closing the internal flow path and adjusting the pressure of a brake fluid supplied to the wheel cylinder; a pressure sensor provided in the base body and detecting the pressure of the brake fluid in the internal flow path; and a control device controlling the opening and closing operation of the control valve based on a detection result of the pressure sensor, in which the control device outputs a control signal of a brake lamp of the straddle-type vehicle based on the detection result of the pressure sensor.