Abstract: A drinking receptacle cover comprises two layers of a rigid resilient material which are circular in shape. An annular downwardly opening channel is formed at the periphery of the two layers which are snugly assembled. This channel receives the top rim portion of a drinking receptacle, and to secure the assembled relation the outer wall of the channel is formed with an inwardly extending bead which engages said rim portion. Both layers have an opening adjacent to the channel. This opening is normally closed by a valve which is generally of the same shape as the opening and also comprises two layers. The lower layer comprises an inner vertical wall and two sidewalls which diverge towards the periphery and are joined at their outer ends by a curved endwall. These side and end walls are formed with a continuous outwardly extending flange. The top layer is also formed with an inner vertical wall, side walls diverging therefrom and a curved end wall.