A removable closure is provided which is particularly useful for closing drinking vessels containing liquid to prevent spillage if the vessel is knocked over. The closure comprises two sections a first section (1) for placement around the top of the drinking vessel. The second section (4) being attachable to the first section (1) in a manner that brings the first section into contact with the exterior of the vessel (7) to provide a liquid tight seal. In a preferred embodiment the second section (4) may be provided with a sealable aperture through which a drinking straw can be inserted whilst retaining the liquid seal around the drinking straw.