Three species of North American freshwater catfishes (Ameiuridae), including Black Bullhead (Ameiurus melas), Brown Bullhead (A. nebulosus), and White Catfish (A. catus), were reported to have been introduced into Irish waters since the late 19th century. However, only isolated specimens of A. melas have been authenticated from two widely separated locations to date: Terenure College Lake, Dublin and Cork Lough, Cork City. During 2006, an unidentified Ictalurid catfish was reported to have been captured by an angler in an undisclosed tributary of the Erne catchment. The author examined two specimens of catfish in the collections of the National Museum of Ireland – Natural History which were obtained from Terenure College Lake during July 1889. Although both specimens were labelled as White Catfish, they proved to be A. melas, one of which was estimated to be 9 years of age. The age of the Terenure specimen suggests that they were probably introduced during the early 1880s, or were the progeny of an already established self-sustaining population introduced at an earlier date. All known records of North American catfishes in Irish waters and their potential invasiveness are reviewed.