Ó Dubhagáin (reformed spelling Ó Dúgáin), anglicised Dugan or Duggan, was the name of a bardic family from Baile Uí Dhubhagáin, in Uí Maine, (now Ballyduggan, Loughrea, County Galway). The family were not related to similarly named family of Dugan of Fermoy, County Cork.
Notable people Seán Mór Ó Dubhagáin (died 1372), Irish poet and historian Tomás Bacach Ó Dúgáin (fl. 1848-1858), scribe Maolsheachlainn Ó Dúgáin (fl. mid-19th century), scribe Liam Ó Dúgáin (fl. mid-19th century), scribe John Doogan (1853–1940), Irish recipient of the Victoria Cross Winston Dugan, 1st Baron Dugan of Victoria (1876-1951), son of a Dugan of County Galway Richard E. Duggan (b. 1952), artist/designer Michael Dugan (b. 1937), General
References http://www.irishtimes.com/ancestor/surname/index.cfm?fuseaction=Go.&UserID=