Thomas was born in Wolverhampton on 5 November 1883, the son of John and Ann Eliza Darby. In 1891 the family were at 3 Penn Road, and Thomas and his parents were joined by six siblings – George E., William Harold, Arthur J., May, Edith S. and Lizzie Ethel. They were at the same address by 1911 (now known as “Stonely House”). Thomas had become a Corporation committee clerk.
Thomas enlisted in the South Staffordshire Regiment (number 268), becoming a 2nd Lieutenant and serving from 5 March 1915. However, in October 1916, he was issued with a Silver War Badge (number 852), indicating that he was no longer able to serve. In 1917, Thomas became a member of the Freemasons, in the Wolverhampton Lodge of Honour, by which date his address was given as 78 Waterloo Road.
He married Margaret Millner in West Bromwich in 1916, and the couple had a son, Douglas J., in Wolverhampton in 1917. Thomas died in Westminster in 1938 at the age of 54.