Abstract: A locking device for a toilet seat lid comprises a rotatable lever arm having a downwardly extending flange mounted adjacent the free end thereof. The lever arm is rotatably mounted on a mounting plate with the latter being fastened to the toilet bowl to the rear of the toilet seat by means of the conventional seat-fastening bolts. The flange cooperates with the free end of the lever arm to present a jaw-like structure for receiving a portion of the rear of the closed lid therein. Upon movement of the closed lid towards an open position the lid engages the jaw-like structure in a manner which opposes movement of the lid towards a fully open position. The lever arm is user-rotatable to a position free of the closed lid to allow opening of the lid and access to the toilet bowl. A spring bias on the lever arm returns the lever arm to the original lid-receiving position upon the lid being returned to its closed position.