Padraig Mac Giolla-Domhnaigh

Dickson—In the district of Ballymoney and surrounding parts, in North Antrim, the surnames Deehan and Deighan have been anglicised Dickson (O'Díochon). Dickson itself is a South-East of Scotland name, having its origin in the English Pale of that country.

Alphabetical Index of Anglicised Surnames in Ireland

See also Woulfe’s Irish Names and Surnames
and O'Hart's Irish Pedigrees