A portable and collapsible storage container formed of rigid, interconnected panels which, when fully assembled, form a self-standing, integrally strong unit and, when collapsed, fold together to occupy a minimal volumetric space. Opposed side walls are hingedly connected to a front frame, and opposed end walls are hingedly connected to a rear wall panel, both to fold inwardly in interlocking fashion such that the side walls overlie the rear panel and the end walls overlie the side walls within the region bounded by the front frame. The storage container may optionally include a door or lid for closure which may be fitted with a lock if desirable. The side walls include means for supporting a removable interior panel to prevent the side walls from folding inwardly which, in turn, prevent the end walls from folding inwardly.