Born in Livonia, Indiana, Dean starred at Indiana University. He was named to the 1921 Helms Foundation All-America team and was named to the all-conference team that year. He won the Big Ten Medal for excellence in athletics and scholarship in 1921. He was Indiana's first All-American.
Dean then became the basketball coach at Carlton College, where he worked for three years. He won two conference championships and amassed a 45-4 record.
He was the hired to be the head baseball and basketball coach at his alma mater, Indiana University, in 1924 and he stayed there until 1938. In 1926 he led the Hoosiers to the school's first conference championship. He won three championships in his fourteen year tenure at Indiana, accumulating a record of 162-93.
In 1938, Dean was named head basketball coach at Stanford University, where he coached the team to the 1942 NCAA championship. His career record was 167-120. Dean is the only unbeaten coach in NCAA tournament history, compiling a 3-0 record in the 1942 tourney. He was named baseball coach at Stanford in 1950, and led Stanford's baseball team to the 1953 College World Series.
Dean is the only coach named to both the Naismith Memorial Basketball Hall of Fame and the College Baseball Hall of Fame. He was also inducted into the Indiana Basketball Hall of Fame in 1965. In 1958 the National Association of Basketball Coaches honored him with the Metropolitan Award. He is a member of Carlton College's "C" Club Hall of Fame.