Nina Mary Benita Douglas-Hamilton, Duchess of Hamilton (née Nina Mary Benita Poore; 13 May 1878 – 12 January 1951), was a British peeress and animal activist.
Douglas-Hamilton was born on 13 May 1878 in Nether Wallop, the daughter of Major Robert Poore and Juliana Benita Lowry-Corry. Her brother, Robert Poore, married Flora Douglas-Hamilton, and three years later on 4 December 1901, Nina married Flora's brother Alfred Douglas-Hamilton, 13th Duke of Hamilton at the parish church, Newton Tony. The couple had four sons and three daughters:
Douglas-Hamilton was very proud of her father's work in helping agricultural labourers and was philanthropic towards the group, but keeping her gifts secret from all but the recipients. One gift was sufficient to completely equip and furnish a home for nurses. She was a co-founder in 1903 of the Animal Defence and Anti-Vivisection Society, with Lizzy Lind af Hageby, a society which set up three veterinary hospitals for horses during World War I, and campaigned against cruelty to animals including the use of animals in war. In 1912 she became a founder of the Scottish Society for the Prevention of Vivisection, which went on to become Advocates for Animals. She also established Ferne Animal Sanctuary, at Ferne House in Dorset, the estate she and her husband owned. She compiled an illustrated book related to the sanctuary called Chronicles of Ferne, published in 1951.
Douglas-Hamilton refused to be operated on for a throat condition due to her opinions on medical research, and when the condition worsened, she refused antibiotics. The condition led to her death on 12 January 1951.