The name Rathmore Avenue derives from Rathmore House, built in 1865 at nearby Dunmurry by Victor Coates, who had purchased approximately 170 acres and developed it as a private estate; the name “Rathmore” (Irish Ráth M(h)ór) meaning “great fort.” The house was situated east of Dunmurry village, off Dunmurry Lane. The building and the site are now occupied by Rathmore Grammar School. Rathmore Avenue, Rathmore Gardens and Rathmore Park are situated nearby in the Erinvale estate.
See also Rathmore Street in East Belfast.