Lowell Juilliard Carr (1885 – 1963) was an American sociologist, prolific author, and long-time professor at the University of Michigan. He is best known for his book Willow Run, which discusses the sociological conditions arising from the wartime increase in the worker population at the Willow Run bomber plant during World War II. He was also a pioneer in the field of studying the underlying social causes for juvenile delinquency.