Thomas Annan (1829–1887) was a Scottish photographer, notable for being the first to record the bad housing conditions of the poor. Born in Dairsie, Fife he was one of seven children of John Annan, a flax spinner.
After his initial apprenticeship to a lithographer in Cupar he moved to Glasgow and, after gaining the patent rights to the photogravure process, established himself in a photographic studio in Sauchiehall Street during 1857. First interested largely in architectural photography and then portraits, in 1866 Annan was commissioned by the Glasgow City Improvement Trust to photograph slum areas. It was this series of photographs, entitled the Old Closes and Streets of Glasgow, that ensured his prosperity.
His other notable works include the building of the Loch Katrine Waterworks, portraits of David Livingstone and Horatio McCulloch, and a series of photographs of the Old Country Houses of the Old Glasgow Gentry.
He was the father of James Craig Annan who continued in his father's profession, receiving a Royal Warrant as 'Photographers and Photographic Engravers to Her Majesty in Glasgow'.
The family business survives to the present day in the form of the Annan Fine Art Gallery, located on Woodlands Road in the West End of Glasgow.
Gallery 8 of the Scottish National Portrait Gallery is devoted to a display of Annan's images.