A hydraulic brake system, including: a brake operation member; a brake device; a master cylinder; a communication switching valve; a low-pressure-source shut-off valve; a high-pressure source; a regulator; a pressure adjuster; and a controller, wherein, when a pressurizing state of the master cylinder is switched from a first pressurizing state to a second pressurizing state after initiation of an operation on the brake operation member, the controller executes a pressurizing-state switching control in which switching of a state of the low-pressure-source shut-off valve from an open state to a closed state and switching of a state of the communication switching valve from a closed state to an open state are carried out after a pressure-regulating state of the regulator has been switched from a first pressure-regulating state to a second pressure-regulating state by controlling the pressure adjuster to increase a second pilot pressure while the first pressurizing state is maintained.