The present study performs free vibration analysis of metal foam joined conical-cylindrical shells (JCCSs) reinforced with graphene platelets. The Donnell’s shell theory is employed to formulate the present model, and centrifugal forces, Coriolis forces as well as initial hoop tensions resulting from rotation are all considered. The continuity conditions including stress resultants and displacements at the interface of the conical and cylindrical shell are expressed. The graphene platelet reinforced material properties are evaluated by the Halpin-Tsai equation. Governing equations are derived via Hamilton’s principle and then they are solved by utilizing the power series method. The results are compared and validated with the available literature and finite element results. Then, different types of porosity and graphene platelet distribution are investigated. In addition, the effect of different regions of graphene platelets reinforced metal foam on JCCSs is further discussed.