Disclosed are an apparatus and method for controlling an oil pump for a vehicle which may control the speed of the oil pump. The apparatus includes a controller configured to control the speed of the oil pump based on the temperature information of a motor and oil and the speed and torque information of the motor, and, when the vehicle is being driven, the controller confirms whether or not a motor or oil temperature is higher than or equal to a first set temperature, controls the speed of the oil pump to a maximum speed value when the motor or oil temperature is higher than or equal to the first set temperature, and calculates a control speed value and controls the speed of the oil pump to the calculated control speed value when the motor or oil temperature is lower than the first set temperature.