An improved circuit breaker locking device is provided that is capable of locking any one of a set of push-pull circuit breaker actuators having shaft and top annular flanges of different diameters. The device includes a pair of opposing body sections, each having a proximal and a distal recess arranged in tandem, and an elastic joining member that joins the opposing body sections together. The proximal and distal recesses of the opposing body sections are sized to capture without frictionally gripping the largest diameter cylindrical shaft section and the largest annular flange of the set of actuators when the body sections are joined together around the actuator. The interface between the proximal and distal recesses is sized to interfere with and prevent passage of the smallest annular flange of all of the actuators.