Thomas Annan (1829–1887) was a Scottish photographer, notable for being the first to record the poor housing conditions of the poor.
Originally from Dairsie in Fife, one of seven children, he moved to Glasgow as an apprentice engraver, and was friendly with a trainee Chemist called, Berwick. They set up business together in 1855 as photographers. Berwick soon left to pursue a medical career.
In 1857 the firm moved to premises in Sauchiehall Street, a lot of business at that time came from photographing country Houses and Mansions around Glasgow. Also photographing paintings whilst at the houses. General landscape views were photographed then sold as individual prints bound into albums.
In 1859 a works was opened at Hamilton. At this time Thomas Annan lived next door to David Livingstone and the explorer's sisters, and took the well known portrait of him. He also took a series of images documenting the new Glasgow Water Work Scheme including a view of Queen Victoria at the Official opening.
In 1868 The City of Glasgow Improvement Trust approached Thomas Annan Thomas Annanto take pictures of some of the slum areas prior to demolition. This is claimed to be one of the first times photography was used as documentary evidence. Exposure times in some cases were measured in minutes