Endohedral metallic fullerenes have been intensively studied in recent years. However, the knowledge of these fullerenes largely came from the investigation of fullerenes encapsulated with lanthanide metals, which present similar physicochemical properties in most of cases. Actinide endohedral fullerenes, though have been known since the beginning of endohedral fullerenes studies, have been unexplored with the respect to their detailed structures and properties. Herein, our study on Th@C₈₂ and U₂C@I_h-C₈₀, for the first time, demonstrated remarkably different electronic and spectroscopic properties of actinide endohedral fullerenes compared to those of lanthanide EMFs. Crystallographic study unambiguously discloses the fine structure of Th@C_3v(8)-C₈₂. Combined experimental and theoretical studies suggest that Th@C_3v(8)-C₈₂ has a surprisingly large electrochemical bandgap of 1.51 eV, which agrees with four-electrons-transfer from the metal to the cage. Moreover, Th@C_3v(8)-C₈₂ displays a strong vibrationally coupled photoluminescence signal in the visible region, which is unprecedented for both fullerene and thorium compounds. The crystallographic and computational studies of U₂C@I_h-C₈₀ reveal a unique axial U=C bond, by far the shortest U-C bond and has never been experimentally proved before.