This review provides a synopsis of the main findings of individual papers in the special issue Terrestrial Biodiversity in a Rapidly Changing Arctic. The special issue was developed to inform the State of the Arctic Terrestrial Biodiversity Report developed by the Circumpolar Biodiversity Monitoring Program (CBMP) of the Conservation of Arctic Flora and Fauna (CAFF), Arctic Council working group. Salient points about the status and trends of Arctic biodiversity and biodiversity monitoring are organized by taxonomic groups: (1) vegetation, (2) invertebrates, (3) mammals, and (4) birds. This is followed by a discussion about commonalities across the collection of papers, for example, that heterogeneity was a predominant pattern of change particularly when assessing global trends for Arctic terrestrial biodiversity. Finally, the need for a comprehensive, integrated, ecosystem-based monitoring program, coupled with targeted research projects deciphering causal patterns, is discussed.