Harrison
Harrison—This name in the first case is the anglicised form in the Isle of Man and in the English mainland counties of the north-west of the Manx name McHarry (Mac Giolla-charraigh or Mac Charraigh) related undoubtedly to the Galloway name of McIlharry. In Co. Mayo the name is the anglicised form of Harrihy (O'h-Earchadha). McHarrie is a Galloway form.
Alphabetical Index of Anglicised Surnames in Ireland
See also Woulfe’s Irish Names and Surnames
… and O'Hart's Irish Pedigrees