The physical structure and design of a three-phase squirrel cage induction motor’s rotor slots have significant effects on its electromagnetic performance. The design of the rotor slot affects the motor’s overall efficiency, torque characteristics, leakage reactance, and air-gap flux density distribution. Using the Finite Element Method Magnetic (FEMM) software, a comprehensive finite element analysis and optimisation framework is created in this study to examine and improve the performance of induction motors by altering the rotor slot design. To investigate their effects on important performance metrics including beginning torque, torque ripple, and rotor copper losses, a number of geometric factors were systematically changed, including slot width, slot depth, slot opening, and corner radius. The electromagnetic fields under various operating situations were precisely captured using a two-dimensional time-stepped finite element model. Torque ripple was assessed and electromagnetic torque was calculated using the Maxwell stress tensor technique. In order to maintain appropriate efficiency and heating constraints, optimisation efforts sought for greater average torque and to limit torque ripple.