William Lennox Cleland (18 January 1847 – 5 November 1918) was a medical doctor in South Australia, for 40 years in charge of Parkside Lunatic Asylum.
Cleland was born in Hong Kong, the eldest son of missionary John Fullerton Cleland ( – 29 November 1901) who migrated to South Australia aboard Gloucester, arriving in Adelaide in August 1852.
He was appointed Resident Medical Officer at the Parkside Lunatic Asylum in December 1878, and Assistant Colonial Surgeon (to A. S. Paterson) in 1879.
When Paterson went on extended leave in 1896 he was appointed Acting Colonial Surgeon, and the position made permanent six months later.
William Lennox Cleland (18 January 1847 – 5 November 1918) married Matilda Lauder "Mattie" Burton (1848 – 1928) on 21 June 1877.