This work presents a model for the optimisation of a permanent magnet synchronous generator for use within a wave energy converter. The model uses genetic algorithms to optimise the internal geometry of the generator (rotor radius, number of pole pairs, etc.) to maximise the electrical power output – by considering the device's electrical efficiency – given historical site data. As part of the model, controllers are optimised for every candidate generator, where the user can select between a linear damping and an impedance matching control strategy. Results show that optimal generator designs have an average gene difference of 29% between a linear damping and impedance matching optimised generator, giving a 32% improvement in electrical power output when using a generator design for impedance matching operation compared to one that was designed for linear damping. This shows the importance of considering generator design and efficiency when building a wave energy converter.