An automatically engageable and quickly and easily releasable locking device for a toilet seat and lid is disclosed. A single mounting bar attached to the underside of the lid carries a pivoted spring-biased locking arm which is released by simple finger pressure and returns automatically to a positive locking position in contact with a stop whenever the lid is closed. No reconstruction or alteration of the conventional toilet bowl or seat and lid structure is required. The locking arm may also be gravity returned to its locking position without spring action.
