Abstract: A golf club locking device attachable to a golf club bag having a main portion divided into one or more compartments and a mouth portion forming openings in the bag for receiving golf clubs in the compartments. The golf club locking device comprises a locking member and a main member which fastens to the mouth of the golf club bag and includes openings corresponding to the compartments., The locking member is coupled to the main member and slides linearly in relation to the main member between a locked position and an unlocked position. In the locked position, the openings are constricted thereby preventing removal of clubs from the golf bag. The locking device is manufacturable as integral component-of a golf bag.