The Ó Dálaigh (Irish pronunciation: [oː ˈd̪ˠaːlˠiː]) were a learned Irish bardic family who first came to prominence early in the 12th century, when Cú Connacht Ó Dálaigh was described as "The first Ollamh of poetry in all Ireland" (ollamh is the title given to university professors in Modern Irish).
The modern Irish surnames O'Daly, Daly, Daley, Dayley, Dalley, Daily, Dailey and Dawley are derived from Ó Dálaigh.