Abstract: A vehicle seat and a quick-release supporting device thereof are provided. The quick-release supporting device includes a limiting member, a carrier, and two engaging structures. The carrier is fastened to the limiting member for carrying an object. The two engaging structures are respectively fastened to two rail holes of the limiting member. Each engaging structure includes an engaging member and a knob. The engaging member has a threaded portion and a positioning fork respectively arranged on two opposite portions thereof, and the threaded portion at least partially protrudes from the corresponding rail hole. The knob is screwed to the threaded portion, so that the engaging member is movable relative to the limiting member for reducing a distance there-between. The two positioning forks can be detachably inserted into two gaps between two headrest clips and a seat back, respectively.