A new spider species, Ero tenebrosa n. sp., is described from La Gomera of the Canary Island archipelago. The new species is diagnosed and illustrated based on a single female only. Barcode data and morphology of the epigyne indicate no close relatives. Distance to nearest barcoded neighbour, Ero furcata (Villers, 1789), is 13.2%. A phylogenetic tree that includes data available at the Barcode of Life Data System clusters the new species along with E. septemspinosaLissner, 2016 as a sister group to the Ero furcata-group. During the identification process, it was realized that Ermetus inopinabilisPonomarev, 2008 is a junior synonym of Ero koreana Paik, 1967; the species is proposed to be transferred to ErmetusPonomarev, 2008. The unknown female of E. laetaBarrientos, 2017 is described from specimens collected in southern Portugal.