William Plane Pycraft (13 January 1868 – 1 May 1942) was an English osteologist and zoologist.
His father was in the Merchant Navy and drowned at Llanelli on 14 August 1868 when William was only 8 months old.
His mother remarried Clement Watson, a Butcher on 14 January 1872 in Great Yarmouth, Norfolk.
In 1892 Pycraft became assistant to Edwin Ray Lankester, and in 1898 moved with Lankester to the staff of the Natural History Museum.
Pycraft wrote many articles and books on natural history, including The Story of Bird-Life (1900), The Story of Fish-Life (1901), The Story of Reptile Life (1905), The British Museum of Natural History (1910), A History of Birds (1910), The Infancy of Animals (1912), The Courtship of Animals (1913), Birds in Flight (1922), Camouflage in Nature (1925) and Birds of Great Britain and their Natural History (1934).