A control apparatus for an automatic transmission includes a torque calculator configured to calculate a torque required during a speed change for a hydraulic clutch at a target speed stage based on an output torque of an engine. A supply fluid pressure calculator is configured to obtain, from the calculated torque, a supply fluid pressure to be supplied to the hydraulic clutch by using a clutch friction coefficient. A fluid supplier is configured to supply the obtained supply fluid pressure to the hydraulic clutch to perform the speed change for an output of the engine through a gear corresponding to the target speed stage. A clutch plate temperature estimating device is configured to estimate a plate temperature of the hydraulic clutch. A fluid pressure correcting device is configured to correct the supply fluid pressure based on the estimated plate temperature.