This review discusses hybrid membrane distillation (MD) systems for desalination, focusing on integration with waste heat and renewable energy sources such as solar, geothermal, and salt-gradient solar ponds. It also covers MD hybrids with pressure-retarded osmosis (PRO), multi-effect distillation (MED), reverse osmosis (RO), crystallization, forward osmosis (FO), and bioreactors for treating concentrated solutions. The paper highlights the advantages of MD, including its low sensitivity to concentration polarization and fouling, and its ability to use low-grade thermal energy. It provides a critical analysis of hybrid MD systems, suggesting future research directions. The review emphasizes the potential of MD in desalination, particularly for seawater desalination, and discusses the integration of MD with other technologies to enhance efficiency and sustainability. It also addresses challenges such as membrane fouling, scaling, and wetting, and suggests improvements in membrane design and system optimization. The paper concludes that MD is a promising desalination technology with potential for widespread application, especially when combined with renewable energy sources and other advanced processes.This review discusses hybrid membrane distillation (MD) systems for desalination, focusing on integration with waste heat and renewable energy sources such as solar, geothermal, and salt-gradient solar ponds. It also covers MD hybrids with pressure-retarded osmosis (PRO), multi-effect distillation (MED), reverse osmosis (RO), crystallization, forward osmosis (FO), and bioreactors for treating concentrated solutions. The paper highlights the advantages of MD, including its low sensitivity to concentration polarization and fouling, and its ability to use low-grade thermal energy. It provides a critical analysis of hybrid MD systems, suggesting future research directions. The review emphasizes the potential of MD in desalination, particularly for seawater desalination, and discusses the integration of MD with other technologies to enhance efficiency and sustainability. It also addresses challenges such as membrane fouling, scaling, and wetting, and suggests improvements in membrane design and system optimization. The paper concludes that MD is a promising desalination technology with potential for widespread application, especially when combined with renewable energy sources and other advanced processes.