Thomas Hamilton (11 January 1784 – 24 February 1858) was a Scottish architect, based in Edinburgh where he designed many of that city's prominent buildings. Born in Glasgow, his works include: the Burns Monument in Alloway; the Royal High School on the south side of Calton Hill (long considered as a possible home for the Scottish Parliament); the Royal College of Physicians of Edinburgh; the George IV Bridge, which spans the Cowgate; the Dean Orphan Hospital, now the Dean Gallery; the New North Road Free Church, now the Bedlam Theatre; Cumstoun, a private house in Dumfries and Galloway; and the Scottish Political Martyrs' Monument in Old Calton Cemetery, Edinburgh.
He was the leading Greek Revivalist in Scotland "more imaginative than his peers and more refined in his detailing". He was a favourite of the church for his Gothic designs, being commissioned to design many Free Churches after the Disruption of 1843. He also designed shops and banks, many of which survive.
He was born on 11 January 1784 in Glasgow. His father, also Thomas Hamilton (1754-1824), had trained as a carpenter but was also an architect, most notable for remodelling the north-west corner of St Giles' Cathedral in 1796. He was presumably watched by young Thomas who was then 12 years old. His father married Hamilton's mother, Jean Stevenson, in the Canongate Church in 1783.