The need for new magnetic, ion conducting and optical materials in the current era of quantum computing, sensing and artificial intelligence, has emerged as an area of renewed significance. However, designing materials for such applications where even slight changes in atomic positions could affected functionality, required accurate atomistic and energetic understanding of materials. Hence, a first-principle Density Functional Theoretical (DFT) study of the electronic and magnetic properties of defected monolayer and bulk MoO₃ was conducted based on methods implemented in Burai version 1.3 and Quantum Espresso version 7.1. Based on these calculations, an indirect band gap of ca. 1.85 eV for bulk MoO₃ obtained from density of states (DOS) and projected density of state (PDOS) reveal the semiconducting nature of this bulk material. Point defect formation energies are calculated using the supercell methodology with a supercell size of 4 x 2 x 4. Substitutional defects including native defects and also the incorporation of vanadium and sulfur were considered for both Mo-rich and O-rich conditions. The effects of such changes in the lattice composition on the magnetic properties of both the bulk and monolayer MoO₃ are also assessed as well as the incorporation of certain defects which could lead to “switchable” magnetic behaviour, controlled by defect concentration with possible quantum computing applications: qubits.