The structural, optoelectronic, magnetic, and elastic properties of cubic perovskite NdInO3 have been analyzed by spin-polarized density functional theory. The computed values of total energies of the optimized systems reveal that ferromagnetic phase is energetically stable rather than paramagnetic phase of cubic NdInO3 compound. Furthermore, the spin-polarized band structure and density of states elucidate the half metallic nature of the studied material due to a different response of both spin channels; spin-up electrons illustrate metallic character, while spin-down electrons display a direct band gap (M–M) semiconducting behavior. The elastic parameters indicate anisotropic and brittle characteristics; further, the total magnetic moment of the cubic NdInO3 perovskite (3 μB) is mainly due to the Nd site with very feeble contribution of In and O atoms. The complete set of optical parameters demonstrate that cubic NdInO3 is active in visible–ultraviolet region. Based on these results, NdInO3 is categorized as a half metallic ferromagnetic compound, which might be used in spintronics and optoelectronic devices.