Abstract Ground source heat pump (GSHP) systems have attracted wide attention in developing energy-efficient buildings. Considering the high upfront cost of GSHP systems, appropriate design and control optimization are essential to enhancing their energy efficiency and reducing the payback period. Since there are many variables influencing the performance of GSHP systems, the commonly used rule-based approaches cannot ensure that the system is designed and operated in an optimal manner. This paper presents an overview of recent advances and development in optimal design and control of GSHP systems, aiming to provide some concluding remarks and recommendations for future research in this direction. The general optimization problems for optimal design and control of GSHP systems are first presented. Sensitivity analysis to determine the major variables to formulate the optimization problems is then discussed. Furthermore, recent progress in optimal design and control of GSHP systems is reviewed. The results showed that an increasing number of single-objective and multi-objective design optimization strategies for GSHP systems have been developed, which seems more robust than commonly used rule-based design approaches. It was shown that optimal control can provide a better operating performance of GSHP systems as compared to rule-based control methods. The majority of studies used a model-based approach to formulate the control problem and model predictive control could play an essential role in renewable integrated GSHP systems. However, studies on optimal control of GSHP systems are insufficient and development of energy-efficient control strategies and evaluation of their control reliability, effectiveness and long-term performance are needed.