A foldable case for foldable mobile electronic devices. The foldable case generally comprises a first shell and a second shell hingedly connected to a third shell. The foldable case is reconfigurable between a closed configuration, an open configuration, and intermediate configurations therebetween. The first, second and third shells comprise cooperative engagement features which allow the first and second shells to hinge or pivot relative to the third shell. The cooperative engagement features also constrain the first and second shells to the third shell and limit the first and second shells to pivotal movements in the open and closed configurations but allow lateral movements in the intermediate configurations.