Postbuckling under high-temperature biaxial compression and thermal postbuckling under uniform thermal loading of functionally graded (FG) graphene origami (GOri)-enabled auxetic metamaterials (GOEAMs) plates are investigated. The plates consist of multiple layers of GOEAMs with varying levels of GOri content in the layers across the direction of the thickness. The nonlinear governing equations of the plate are based on the first-order shear deformation theory (FSDT) and the von Kármán type nonlinear strain–displacement relationship. The mechanical and thermal postbuckling equilibrium paths of FG-GOEMA plates on the elastic foundation are determined using the two-step perturbation method. The effects of the elastic foundation, temperature, GOri content, GOri distribution pattern, and degree of GOri folding on the mechanical and thermal postbuckling of FG-GOEMA plates are discussed.