Ternary nitrides, which consist of two metal cations and a nitrogen anion, exhibit considerable potential as innovative semiconducting materials due to their efficient conductivities and large melting temperatures. This study represents a pioneering investigation that employs density functional theory (DFT) calculations, utilizing the CASTEP code, to examine the influence of bi-axial strain on the semiconductor MgZrN2, which possesses a rocksalt tetragonal crystal structure. The primary objective is to analyze the variations in the structural and optoelectronic properties resulting from this strain. The material’s optoelectronic characteristics undergo notable changes when subjected to bi-axial strain. Indeed, when subjected to bi-axial ranging from −4% to +4%, the band gap also experiences a noticeable variation towards lower energy levels. Based on computational analysis, it has been determined that MgZrN2, a material deprived of magnetic properties, exhibits a direct band gap. To figure out the nature of bonding among the atoms in the material under discussion, Mulliken analysis and bulk electron density difference (EDD) are done as well. Mulliken analysis and EDD reveal that the ZrN bond in MgZrN2 is covalent, whereas the MgN bond is ionic. The optical absorbance of the material may be manipulated within the visible and ultraviolet spectra, and it also demonstrates a disordered nature. The compound’s optical properties indicate its suitability for implementation into components of devices designed for operation within the visible or ultraviolet (UV) parts of the electromagnetic spectrum. Furthermore, to determine the material’s suitability for solar cell applications, we compute the Spectroscopic Limited Maximum Efficiency (SLME) at bi-axial strains of −4%, 0%, and 4%. The SLME value reaches its maximum at +4% strain, equivalent to 18.7%. Undoubtedly, MgZrN2 possesses considerable potential for a wide range of solar cell applications.