Fabian Leendertz studied veterinary medicine at the University of Budapest and the Freie Universität (FU) Berlin. In 2005, he became a doctor of veterinary medicine and group leader of the Primate Diseases Group at the Max Planck Institute for Evolutionary Anthropology in Leipzig. Then he became head of the Emerging Zoonoses Junior Research Group at the Robert Koch Institute (RKI) Berlin until 2012 and qualified as a specialist veterinarian in microbiology. As head of the RKI project group Epidemiology of Highly Pathogenic Pathogens (2012 - 2021), he habilitated in microbiology at the FU Berlin in 2016. In 2021, Fabian Leendertz was appointed founding director of the Helmholtz Institute for One Health (HIOH) in Greifswald and professor of One Health at the University of Greifswald.

Fabian Leendertz's major achievements include the discovery of a new type of anthrax pathogen (Bacillus cereus bv anthracis) and the first description of leprosy in wild apes. In addition, he led the investigation into the point of origin of the West African Ebola outbreak in 2014 and is a member of the WHO expert group investigating the origin of SARS-CoV-2. In recognition of his commitment to implementing One Health Approaches, he was awarded the United Nations Environment Programme (UNEP) Champion of the Earth Award in 2020. He also serves on several advisory boards, including the Scientific Advisory Board of the National Zoonoses Research Platform, the Advisory Board of the One Health Initiative of the German Federal Ministry for Cooperation and Development, and the Scientific Commission of UNEP's Great Apes Survival Partnership.