The present invention provides a steering angle estimating apparatus for vehicle that can accurately determine a steady state at all the steering angles, and can estimate the steering angle as much as possible even in a non-steady state. In the steering angle estimating apparatus for vehicle that has wheel rotational velocity sensors for four wheels, respectively, and estimates the steering angle of the vehicle based on wheel rotational velocities from the wheel rotational velocity sensors, relationships in the wheel rotational velocities between respective combinations of two wheels of the front and rear wheels on right and left sides are compared so that slip of the four wheels is detected.