Abstract: A liquid dispenser for being affixed to the neck of a liquid-filled container or bottle comprises a cap having a spout and a vent, an inner core for insertion in a cylindrical inner cavity of the cap and a stopper assembly attached to the inner core. The cap is rotatable about the inner core and stopper assembly between an open and closed position. Dispensing channels and venting channels in the core and stopper assembly align with the spout and vent in the cap in the open position. The dispensing channels and venting channels are disconnected from the spout and vent in the closed position. Various provisions are made so that the dispenser will be leak-proof in storage and in use. A tamper-evident arrangement is included in a portion of the dispenser. Specific features are provided in the neck of a bottle upon which the dispenser is to be affixed in order to position and lock the dispenser in place.