According to a pedigree of the Walshes of Mayo compiled in 1588, one "Walynus", who arrived in Ireland in 1169, is said to have been the progenitor of the Walshes of Tirawley in Co. Mayo, and the brother of Barrett, the ancestor of the Barretts of the same county. The western family, originally based around Killala, were thoroughly absorbed into Gaelic society very quickly. Their chief was known as Mac Bhaitin (or MacVattin) from Battin Barrett, who lived in the 13th century. This name may also have been anglicised as Padden, a name commonly found in Mayo today. In the middle ages the family began to split into various sub-clans, along Gaelic lines, and created a number of new surnames, among them McAndrew, Timmons and Roberts. The Cork settlers were not so Gaelicised, giving their name to the large barony of Barretts in the middle of the county.
The arms of the family are based on word play, a pictorial version of barrettes, in French "short bars".
.Richard Barrett (1740--1818), of the Mayo family, was well known as the "Poet of Erris" and was active in the United Irishmen.
The last public hanging to take place in England was that of Michael Barrett, a member of the Fenians who attempted to blow up Clerkenwell prison It took place in 1868.
Paul Barrett (1954 - ) is a well-known Dublin jazz musician and a trombonist of some note.
Roger "Syd" Barrett, songwriter and guitarist, joined the rock group Pink Floyd in 1966 and was instrumental in their rise to fame. Songs such as "Arnold Layne" and "See Emily Play" (both 1967) were remarkable for their unusual chord changes and psychedelic subject matter..