Knocknarea is an anglicization of an Irish name. Knock means hill, but the etymology of the rest of the name is disputed. The Placenames Database of Ireland gives the Irish name as Cnoc na Riabh (meaning hill of the stripes). However, P.W. Joyce preferred the interpretation Cnoc na Riaghadh (hill of the executions). Cnoc na Riogha (hill of the kings) has also been suggested, as has Cnoc na Ré (hill of the moon).