Gilbert Percy Whitley (9 June 1903 – 18 July 1975) was a British-born Australian ichthyologist and malacologist who was Curator of Fishes at the Australian Museum in Sydney for about 40 years. He was born at Swaythling, Southampton, England, and was educated at King Edward VI School, Southampton and Osborne House. He died in Sydney.
Whitley migrated with his family to Sydney in 1921 and he joined the staff of the Australian Museum in 1922 while studying zoology at Sydney Technical College and the University of Sydney. In 1925 he was formally appointed Ichthyologist (later Curator of Fishes) at the Museum, a position he held until retirement in 1964. During his term of office he doubled the size of the ichthyological collection to 37,000 specimens through many collecting expeditions.
Whitley was also a major force in the Royal Zoological Society of New South Wales, in which he was made a Fellow in 1934 and which he served as President during 1940–41, 1959–60 and 1973–74. He also edited its publications from 1947 to 1971.