The present invention is directed to a thermal insulating sleeve for a container that is easily converted from a generally planar configuration during periods of nonuse and into an expanded or open configuration for receiving a container during periods of use. In a preferred embodiment of the invention, the thermal insulating sleeve comprises a plurality of side panels defining a generally tubular body positioned about an imaginary longitudinal axis having an open first end and a second end forming a central cavity therein. Circumferential positioned about the open first end and equally spaced one from another, is a plurality of fingers that extend generally radially inwardly into the central cavity and are angled generally downwardly with respect to the tubular body and are effective for stabilizing the container within the central cavity and for providing an insulating layer of air between the container and the tubular body. In a preferred embodiment of the invention, the thermal insulating sleeve further comprises a bottom.