The physical properties of Na-based NaXO3 (X = Ge, Si) oxide-perovskite have been explored within the density functional theory (DFT)-based CASTEP code. Both compounds have a cubic shape with a space group Pm3m. Thestructural stability of these compounds has been assessed byemploying the formation enthalpy computations. Regarding the electronic properties, it was found that NaGeO3 and NaSiO3 are p-typesemiconducting materials with an indirect band gap. The total density of states (TDOS) and partial density of states (PDOS) confirm the amount of electron concentration in specific bands. Both materials absorb light more strongly, in the ultraviolet spectrum. Therefore, we believe these materials are good candidates for electronics and optoelectronic applications associated with collecting UV light. It is also found that the cubic forms of both compounds simplify their mechanical stability. These results not only enhance our understanding of NaXO3 materials but also open up new possibilities for the potential applications of these materials in various technological applications.