John McConnell Black (28 April 1855 – 2 December 1951) was a Scottish botanist who emigrated to Australia in 1877 and eventually documented and illustrated thousands of flora in South Australia in the early 20th century. His publications assisted many botanists and scientists in the decades that followed. He was the younger brother of theatre and hotel manager Helen Carte. The standard author abbreviation J.M.Black is used to indicate this person as the author when citing a botanical name.