A valve unit for a tensioning device of an endless drive is provided, in particular a chain drive of an internal combustion engine, with a carrier plate having an underside forming a contact surface and an upper side which can be faced towards a pressure chamber of the tensioning device, and a valve body which is guided in a receptacle movably relative to the carrier plate for opening and closing a valve seat of the tensioning device. Such a valve unit is to be simplified and more cost-saving. The receptacle is formed by the carrier plate and a suspension device is provided in the region of the receptacle on which the valve body is suspended from the carrier plate in a lowermost position. The carrier plate is horizontal in the non-installed state of the tensioning device, such that the valve body projects downwardly out of the receptacle and is movable upwardly by at least the opening stroke. The invention relates to a corresponding hydraulic tensioning device.