Ian James Ferguson-Lees (8 January 1929 in Italy – 11 January 2017) was a British ornithologist. He became known as a member of the British Birds Rarities Committee who was responsible, with John Nelder and Max Nicholson, for publicly debunking the Hastings Rarities.
Ferguson-Lees spent his early years in Italy and France, but was educated in Bedford, England. He turned down the chance to study zoology at Oxford University in order to get married, and became a teacher for seven years. As a boy, he was taught about birds by Bernard Tucker.
He was also a twitcher, once driving through the night to see a dusky thrush at Hartlepool. In 1952 Max Nicholson persuaded him to become Assistant Editor of British Birds, then two years later, Executive Editor.
Ferguson-Lees was a member of the British Birds Rarities Committee from 1959 to 1963 and was responsible, with John Nelder and Nicholson, for debunking the Hastings Rarities - a series of rare birds, preserved by a taxidermist and provided with bogus histories.
He has made a particular study of peregrines and dunnocks.
He died on 11 January 2017.
He had two sons and two daughters.