We describe the new species, Nesticus pecki, an apparently cave-limited (but not troglomorphic) species from the southeastern edge of the Cumberland Plateau in southern Tennessee. Previously unknown males of N. dilutus Gertsch, N. stygius Gertsch, and N. furtivus Gertsch are illustrated and described. These male specimens, along with additional females, are all taken from their respective type localities. Nesticus valentinei Gertsch is considered a junior subjective synonym of N. barri Gertsch (new synonymy). Several cave-limited species in the region are single-site endemics, including N. furtivus, N. dilutus, and N. pecki. We discuss the conservation status and biological factors that may potentially threaten the continued existence of these populations.