The plow lock is a device that is adapted for use with a plow or a snowplow in order to immobilize the plow or snowplow from use. The plow lock includes a first plate affixed to a second plate. The second plate forms a right angle with the first plate. The first plate includes a first lock hole thereon. The second plate is further defined with an outer surface. The outer surface of the second plate is affixed to a wedge member. The wedge member extends outwardly from the second plate. The plow attachment bracket includes a plow lock hole that aligns with the first lock hole of the first plate such that a lock is locked thereon so as to secure the plow lock onto the plow attachment bracket thereby preventing a vehicle from attachment to the plow attachment bracket.