Thankfully local genealogist and historian Brian Mitchell has the answer having sorted the Dohertys from the McLaughlins, and the Gallaghers from the Kellys, in his book ‘The Top 300 Surnames of Derry-Londonderry’, published by Clearfield in Baltimore in the United States.
The book is based on the 1989 Foyle Community Directory, which lists 1,860 unique surnames in Derry City.
Brian looked at the number of entries and ranked the surnames in order of mentions. Where is yours in the list?

21. 20. Thompson.
20. Thompson. English and Scottish: Meaning son of Thomas this surname, spelt as Thompson, was the 15th commonest name in England and, as Thomson, was the fifth commonest in Scotland. This distinction in spelling, however, was not perpetuated in Ulster. The Thomsons were one of the lesser riding clans of the Scottish Borders; many of whom settled in County Fermanagh during the 17th Plantation of Ulster. In the Highlands of Scotland a number of distinct septs of McThomas anglicised their name to Thomson and to McCoombe and Holmes (Brian Mitchell). Thompson ranks 20th in the list with 65 mentions. Pictured is Angela Thompson, Lecturer in Health and Social Care at NWRC, with her son Benjamin. Photo: Martin McKeown.

22. 19. Jim Barr.
19. Jim Barr. Scottish: Derived from various place names in southwest Scotland, meaning height or hill. English: The name has various origins including: a local name for someone who lived by a gateway or barrier; an occupational name for a maker of bars; and a nickname for a tall, thin person (Brian Mitchell). Barr ranks 19th on the list with 65 mentions. Pictured is Jim Barr, founder of the official Derry Republic of Ireland supporters club. Photo: Kevin Mullan

23. 18. Duffy.
18. Duffy. Irish: Two distinct septs of this name originated in Ulster, one in Monaghan, who were based at Clontibret, the other in Donegal, where they were hereditary tenants of the church lands at Templecrone. Scots Gaelic: A sept of Clan MacFie who trace their descent from Kenneth McAlpine, the 9th century King of Scots. Meaning 'son of the black one of peace' this clan's home was on the island of Colonsay in the Hebrides (Brian Mitchell). Duffy ranks 18th on the list with 68 mentions. Pictured is Ireland and Norwich central defender Shane Duffy. Photo: Charles McQuillan

24. 17. Quigley.
17. Quigley. Irish: By the end of the 16th century this sept, which originated in County Mayo, had become dispersed with its main concentration located in Counties Derry and Donegal. A sept called Quigley also originated in the Irish peninsula, County Donegal. Quigley ranks 17th on the list with 69 mentions. Pictured, legendary Derry jazz musician Johnny Quigley, on left, with the late maestro Gay McIntyre. Photo: Jim McCafferty

