The Thomas surname is of patronymic origin, that is, it is based on the first name of the father. In this case, it means "son of Thomas". The Thomas surname is found throughout the United Kingdom, but is generally considered to be Welsh in origin.

According to Harleian Manuscripts, which in many cases are the first recorded existence of a family's lineage, the name Thomas was recorded in the following main counties: BUCKINGHAMSHIRE, CORNWALL, HEREFORDSHIRE, KENT, MIDDLESEX, SURREY, and SUSSEX. Harleain manuscripts were recorded for English and Welsh families during the time after the Conquests, roughly between 1530 and 1700.