An apparatus and method for controlling articulation of an articulated vehicle may prevent jackknifing of the articulated vehicle driven backwards. The apparatus includes a hitch angle calculator configured to calculate a desired hitch angle based on a steering angle and a speed of the articulated vehicle, an error calculator configured to calculate an error between the desired hitch angle and an actual hitch angle of the articulated vehicle, a moment generator configured to generate a moment for controlling the articulation of the articulated vehicle based on the error, and an articulation controller configured to control the articulation of the articulated vehicle based on the moment.