O'Donovan (Irish: Ó Donnabháin [oːˈd̪ˠɔn̪ˠəˌvˠɑːnʲ]) or Donovan is an Irish surname, deriving from Donovan who was slain in 977 A.D. It is also written Dhonnabháin in certain grammatical contexts, and Donndubháin, being originally composed of the elements donn, meaning dark brown, dubh, meaning dark or black, and the diminutive suffix án. Ó derives from the earlier Ua, meaning grandson or descendant. The spelling of the name during the 16th and 17th centuries included Donevan, Donevane, Donovane, and other iterations. Pronunciation of the name in Ireland is closest to "Dunaven".

The O'Donovans are descendants of the 10th century Donnubán mac Cathail, ruler of the regional or sub-provincial kingdom of Uí Fidgenti, as well as of his royal Norse relations from Limerick and Waterford, believed to belong to the Uí Ímair. From his accession to the kingship in 962 to the death of Amlaíb Ua Donnubáin in 1201, the family operated as a semi-independent to sometimes fully independent regional ruling house within the larger provincial kingdom of Munster. In the 13th century the O'Donovans surrendered principal sovereignty to the Kingdom of Desmond and later Carbery, after playing a role in the formation of the latter principality. However, the leading dynasts of the family became semi-sovereign princes or flatha underneath the MacCarthy Reagh dynasty in Carbery, or perhaps even local petty kings.^[5] Nearly five centuries later and eighty years after the fall of the Gaelic order, the O'Donovans were one of the few families of Carbery and Munster still allowed by the authorities to be of royal extraction.

 Today the head of the family is still counted among the leading Gaelic nobility of Ireland . Morgan Gerald Daniel O'Donovan (Murchadh Gearóid Dónal Ó Donnabháin) is The O'Donovan, Chief of his Name and Arms, formerly styled Lord of Clancahill. Born in Pau, France, in 1931, the son of the late Morgan John Winthrop O'Donovan, The O'Donovan, by his wife Cornelia Bagnell (died 1974), he succeeded to the Chiefship in 1969. Educated at Stowe and Trinity College, Cambridge, The O'Donovan resides near Skibbereen, in West Cork. O'Donovan, now retired, was until recently a member of the General Synod of the Church of Ireland, and has served as Chairman of the Standing Council of Irish Chiefs and Chieftains

http://www.iol.ie/~kevnilse/eoghantx.html

http://www.aughty.org/pdf/ancient_cork.pdf

http://www.rootsweb.ancestry.com/~fianna/history/milesian.html

4.      Uí Fidgeinti- The name of the ancient group the O’Donovan’s are descended from . They were originally from the Limerick area.