Lynn Thorndike (born 24 July 1882, in Lynn, Massachusetts, USA – died 28 December 1965, Columbia University Club, New York City) was an American historian of medieval science and alchemy.
He was the son of a clergyman, Edward R.
Thorndike, and the younger brother of Ashley Horace Thorndike, an American educator and expert on William Shakespeare, and Edward Lee Thorndike, known for being the father of modern educational psychology.