The youngest son of engineer Robert Stevenson, and brother of the lighthouse engineers Alan and David Stevenson, between 1854 and 1886 he designed many lighthouses, with his brother David, and then with David's son David Alan Stevenson. He married Margaret Balfour and their son was the writer Robert Louis Stevenson, who caused him much disappointment by failing to follow in the engineering of his family.

Thomas Stevenson was a devout and regular attender at St. Stephen's Church in St Stephen's Place, Silvermills, at the north end of St Vincent Street, Edinburgh.

He was involved in regrettable efforts to rubbish the inventions of John Richardson Wigham.