In this letter, a linear enthalpy correlation, developed from the Sverjensky–Molling linear free energy relationship has been used to calculate the standard enthalpy of formation of the particular crystalline actinide dioxides (AnO 2) from the known thermodynamic properties of the corresponding aqueous cations (An 4+). Using the linear enthalpy relationship, the standard enthalpies of formation of various AnO 2 are calculated. Since some actinide dioxides are difficult for testing, such linear enthalpy correlation may provide a useful tool for predicting unknown thermodynamic properties from a limited number of available data.