A ladder tray assembly includes a case that has a recess integrated therein. A lid is hingedly coupled to the case for opening and closing the case. A pole is extendable through the case and the pole is inserted into a rung of a ladder thereby mounting the case to the ladder. A case member is coupled to and extends away from the case and a grip is coupled to the case member. The grip extends around the pole when the pole is extended through the case and the grip extends around the rung through which the pole is extended. A pair of storage units is each attachable to the lid when the lid is in an open position to facilitate tools stored in the storage units to be accessible to a user.