Thompson An English and Scottish surname meaning son of Thom, in Ulster it is mostly of Scottish origin and spelt Thomson. In Scotland: A family possessed of Duddingston near Edinburgh, in Pertshire. A sept of Clan Campbell in Argyllshire, really Mac Tavishes by Mac Thomais Clan Tavish of Dunardarig descendent of Tavis Conn second illigimate son of Gillespick son of Callen Mor Maith. In 1890 Thompson was the forty-second most numerous surname and the estimated number of bearers was 14,200. It was the most common surname in Down and the surname was principally to be found in Antrim, Down, Armagh, Derry, Dublin, Fermanagh and Longford. In the United States Taylor is the 10th most numerous surname with an estimated 855,250 bearers. In England and Wales in 1996 it was the 4th most numerous surname. In Scotland in 1995 it was the 13th most numerous surname.