Simple SummarySea turtles are currently endangered due to several factors, including infectious and parasitic pathogens. Opportunistic and pathogenic bacteria are largely present in the marine environment and may infect and cause diseases in sea turtles and other animals. Even though infected sea turtles are not a relevant source of infections for humans if compared to other animals, they may be involved in the epidemiology of zoonotic bacterial agents, including those that are antimicrobial resistant; therefore, the direct and indirect contact of humans with sea turtles, their products, and the environment where they live may represent a One Health threat.AbstractSea turtles are important for the maintenance of marine and beach ecosystems, but they are seriously endangered due to factors mainly related to human activities and climate change such as pollution, temperature increase, and predation. Infectious and parasitic diseases may contribute to reducing the number of sea turtles. Bacteria are widespread in marine environments and, depending on the species, may act as primary or opportunistic pathogens. Most of them are able to infect other animal species, including humans, in which they can cause mild or severe diseases. Therefore, direct or indirect contact of humans with sea turtles, their products, and environment where they live represent a One Health threat. Chlamydiae, Mycobacteria, and Salmonellae are known zoonotic agents able to cause mild or severe diseases in sea turtles, other animals, and humans. However, other bacteria that are potentially zoonotic, including those that are antimicrobially resistant, are involved in different pathologies of marine turtles.