It was once popular in the 16th-century in Leinster, Munster, parts of Connacht and in County Tyrone in Ulster, and was Anglicised as O'Kenna, O'Kenny, O'Kinney, Kenna, Kenney, Kenny, and Kinney amongst other variations.
[1] One bearer of the name was Cainnech of Aghaboe, better known in English as Saint Canice - a sixth-century Irish priest and missionary from near Dungiven, after whom the city and county of Kilkenny is also named.
The Irish form Cill Chainnigh means "Church of Canice".
It is thought that the Ó Cionnaith sept was part of the Uí Maine kingdom, based in Connacht.
Kenny is ranked at number 76 in the list of the most common surnames in Ireland.