A vehicle restriction mechanism and a vehicle carrier including the same are provided, and the vehicle restriction mechanism is configured to be disposed on a supporting arm of the vehicle carrier and includes a base and a stem member. The base includes a sleeve portion, and the sleeve portion defines an axial direction. The stem member is adjustably positioned on the sleeve portion, and the stem member is rotatable between a restricted position and a release position relative to the base about the axial direction. One of the base and the stem member has a first guiding portion, and the other of the base and the stem member has a second guiding portion movably connected with the first guiding portion. Relative to an outermost bottom surface of the base, heights of at least two parts of the first guiding portion are different in the axial direction.