Unlike more established renewable energy conversion technologies, such as wind turbines, wave power systems have reached neither commercial maturity, nor technological convergence. The significant variation in device geometries and operating principles has resulted in a diversification of effort, with little coordination or true comparative analysis. The situation is compounded by the relative lack of systematic optimisation applied to the sector, partly explained by the complexity and uncertainty associated with wave energy system models, as well as difficulties in the evaluation of appropriate target function metrics. This review provides a critical overview of the state-of-the-art in wave energy device geometry optimisation, comparing and contrasting various optimisation approaches, and attempting to detail the current limitations preventing further progress, and convergence, in the development of optimal wave energy technology.