Abstract: A hybrid vehicle control system configured to perform a control of a hybrid vehicle includes a transmission control unit, a motor control unit, and an engine and hybrid vehicle integrated control unit. The transmission control unit sends sudden deceleration determination permission information when a predetermined permission condition is satisfied at a time of electric vehicle traveling in which an engine is stopped, a clutch is disengaged, and the hybrid vehicle is driven by an electric motor. The clutch is interposed between the engine and a continuously variable transmission. The motor control unit performs a sudden deceleration determination of the hybrid vehicle when receiving the sudden deceleration determination permission information, and performs reduction of output torque of the electric motor when determining occurrence of sudden deceleration.