The Black Harrier (Circus maurus) is listed as Endangered by the IUCN and is an endemic, range-restricted habitat specialist within southern Africa. Our study aimed to assess the current and potential future changes in the distribution of the Black Harrier, as well as to quantify the most suitable areas within both the “breeding range” (i.e., areas used for nesting) and the “all-year-round range” (i.e., areas used by Black Harriers during breeding and non-breeding periods). Using tracking data of 13 tagged adults and 307 nest locations collected from 2000-2015, we implemented a Species Distribution Modelling workflow, making use of a data-driven process of variable selection and model optimization. Model optimization included hyper-parameter tuning, which is the process of finding the optimal settings for model parameters to improve predictive performance. Additionally, we used General Circulation Models and three Shared Socioeconomic Pathways to assess the potential impact of climate change on the geographical distribution of the Black Harrier. Our study shows that a disproportionately low percentage (32%) of the area currently climatically suitable for the Black Harrier hosts suitable breeding habitat for the species. Climate change modelling projects extensive range contractions (up to 83%) of both Black Harrier breeding and all-year-round ranges by 2061-2080. Core areas of the projected future range are in the coastal, Overberg, and mountain Fynbos/Renosterveld regions of the Western Cape province of South Africa. Furthermore, only ca. 20% and 10% of Black Harrier’s breeding and all-year-round ranges, respectively, fall within Protected Areas (PAs). Prioritising, protecting, and managing the remaining habitat patches within the projected future range by including them within PA networks, will be critical to promote the persistence of the Black Harrier.