Other branches of the clan: Kealy, Quealy, Queally, Queely, Keily, O'Keily, Kehelly, Kehilly, Coakley, MacKilkelly, Gilkelly, Killkelly, Kilkelly.
Irish Clan Name: O'gCeallaigh, O'Ceallaigh.
Scottish form: Kelley, Kellie.

There are approximately 50,000 Kellys and O'Kellys in Ireland to-day. It is the second commonest Irish surname, not far behind Murphy in numerical strength. This name presents a remarkable example of the extent to which the prefixes O and Mac, so widely dropped during the period of Gaelic submergence, have been resumed. In the year 1890 there were 1,242 births registered as Kelly (distributed all over the country) while only nine were registered as O'Kelly. Today the proportion has risen from one in 130 to approximately one in twenty. The universally respected President of Ireland Mr. Sean T. O'Kelly, (previous President) is a case in point.

Ahascragh, Kilconnell and Aughrim are part of the ancestral home of the Kellys / O'Kellys and form a stage of the Beara-Breifne Greenway which is based on the historic march of O'Sullivan Beara in 1603.