Thomas Wilson was born on February 5, 1880 to Thomas Wilson and Mary Scott Wilson (nee Greive) at Roberton near Hawick in the Scottish Borders.
His father, Thomas Wilson, was schoolmaster at Roberton, a position he held for over 50 years. He married Mary Scott Greive on December 29, 1875 at the parish church in Ashkirk, several miles north of Hawick. They had five children: James (Jim), Margaret, Thomas, Christina (Chrissie) who was a schoolteacher for many years at Ashkirk, and George, a doctor who practiced medicine in Redditch, England.
Thomas spent his childhood at the School House in Roberton. After leaving school he became a civil engineer and an Associate Member of the Institution of Civil Engineers (A.M.I.C.E). He worked as a civil engineer in Carlisle, England, in Glasgow and latterly in Malaya where he was working when war was declared in 1914.