A planetary health perspective views human health as a function of the interdependent relationship between human systems and the natural systems in which we live. The planetary health impacts of climate change-induced ocean biodiversity loss are little understood. Based on a systematic literature review, we summarize how climate change-induced ocean warming, acidification, and deoxygenation affect ocean biodiversity and their resulting planetary health impacts. These impacts on the planets’ natural and human systems include biospheric and human consequences for ecosystem services, food, and nutrition security, human livelihoods, biomedical and pharmaceutical research, disaster risk management, and for organisms pathogenic to humans. Understanding the causes and effects of climate change impacts on the ocean and its biodiversity and planetary health is crucial for taking preventive, restorative, and sustainable actions to ensure ocean biodiversity and its services. Future courses of action to mitigate climate change-related ocean biodiversity loss to support sound planetary health are discussed.