Thomas Smith (1752–1814) was a Scottish businessman and early lighthouse engineer. Born in Broughty Ferry, Dundee, his father drowned in Dundee harbour when he was young. His mother encouraged him into a career away from the sea, leading him into working in ironmongery.
By his 30s, he was running his own business making lamps and designing street lighting for the burgeoning New Town, Edinburgh. His success with innovative reflectors on lights led him to search for new business by contacting the newly formed Northern Lighthouse Trust (now Northern Lighthouse Board). He was appointed the first engineer to the Trust contracted to build the first four lighthouses (Kinnaird Head, Mull of Kintyre, Eilean Glas, and North Ronaldsay).
In 1787, he had been twice widowed and had three young children when he met and married Jean Lillie Stevenson, a widow whose young son was Robert Stevenson. Robert became Smith's apprentice, business partner, son-in-law and eventual inheritor of the lighthouse building business.