A movable connector positioning mechanism and method for preventing unnecessary movement of a movable connector before fitting to a mating connector so that the movable connector can be located and held in a proper position to eliminate misregistration between the movable and mating connectors. The movable connector is mounted to a mounting member having a mounting hole. The mechanism includes a support plate which is integral with a connector housing of the movable connector and includes a retaining portion which projects from one side of the support plate and is adaptable for insertion into a mounting hole. The mechanism further includes a positioning member having a first component on the mounting member and a second component on the support plate, which engage to prevent rotation of the retaining portion about an axis of insertion of the retaining portion so as to locate the connector housing in a predetermined position when the retaining portion is being inserted into the mounting hole. The first component is a hole and the second component is a projection or vice versa. The engagement of the first and second projections is released as the movable connector is being mated with the mating connector.