A rotation induction device for a vehicle includes: an upper case formed of a synthetic resin material, and having a piston rod passing therethrough; a lower case formed of a synthetic resin material and disposed under the upper case, wherein the piston rod passes through the lower case; a center plate formed of a synthetic resin material, disposed between the upper case and the lower case such that the piston rod passes through the center plate, and configured to induce the rotation of either one or both of the upper case and the lower case; and an inflow prevention part formed on either one or both of the upper case and the lower case, and configured to block an inflow of foreign matter through the piston rod.