Hugh Welch Diamond (1809 – 21 June 1886) was an early British psychiatrist and photographer who made a major contribution to the craft of psychiatric photography.
Diamond was educated at Norwich School and later studied medicine at the Royal College of Surgeons in 1824.
He wrote many articles and was a popular lecturer, and he also sought to encourage younger photographers.
Among the latter was Henry Peach Robinson, who was later to refer to Diamond as a "father figure" of photography.
Recognition for his encouragement and for his willingness to share his knowledge came in 1855, in the form of a testimonial amounting to £300 for services to photography; among those who subscribed were such people as Delamotte, Fenton and George Shadbolt.