A comprehensive study of the floristic diversity of Agguttinni Territorial Park, Nunavut’s newest and largest Territorial Park, has documented 141 vascular plant, 69 bryophyte, and 93 lichen species from this unique protected area on northern Baffin Island. Through a combination of extensive fieldwork in 2021 and examination of hundreds of existing herbarium specimens, the authors have documented species newly reported for Baffin Island and have crafted a biodiversity baseline important for park management and conservation.