Abstract: A beverage container sleeve includes a body having an accordion configuration provided with a centrally registered longitudinal axis. The body includes an exterior surface and an interior surface oppositely position therefrom wherein the interior surface preferably includes a thermally insulative layer. The body further includes an upper portion, a bellowed portion, and a lower portion. Advantageously, the bellowed portion interconnects the upper portion to the lower portion. In this manner, the bellowed portion is configured to be selectively compressed and decompressed between folded and unfolded position such that, when the bellowed portion is compressed to the folded position, the bellowed portion is outwardly displaced away from the centrally registered longitudinal axis and thereby has a greater latitudinal width and a shortened longitudinal length.