170 species of bryophytes, including 141 species of mosses, and 29 species of liverworts are reported from Delaware County, New York. A total of 48 new county records have been recorded. Ulota drummondii, a species previously unknown from New York State, as well as the rare species Plagiothecium latebricola are among the species reported new for the county. This flora is the first known county-wide bryophyte survey in the Catskills Region of New York State. After examination of collections from herbaria, field surveys were conducted during the spring and summer months of 2013 and 2014. To ensure sufficient sampling across the county, two sampling regions were selected from within each of the county's 19 townships. The location of each sampling region was determined using USDS land cover data in order to capture as much habitat diversity as possible. Floristic habitat sampling was then used at each of the thirty-eight collection sites.