Gillagori Ua Dubhacan (died 1167) was Abbot of Aran, Ireland.
Gillagori appears to be otherwise unknown. His surname may be an early form of Ó Dubhagáin. They were a bardic family from Baile Uí Dhubhagáin (Ballyduggan), near Loughrea, County Galway.
More notable bearers of the name would include Seán Mór Ó Dubhagáin (died 1372), Patrick Duggan, Bishop of Clonfert (died 1896), and Winston Dugan, 1st Baron Dugan of Victoria (1876–1951).
Gillagori appears to be the last-known abbot of Aran.