Man Mountain Dean (born Frank Simmons Leavitt, June 30, 1891 - May 29, 1953) was a professional wrestler of the early 1900s.

He was born in New York City and from childhood was remarkably large in stature. This trait led to a lifelong interest in competitive sport, and also made it easy for him to lie about his age in order to join the Army at the age of fourteen. While enlisted he saw duty on the Mexican-U.S. border with John J. Pershing, and was later sent to France where he participated in combat during World War I. Also during this period (1914) he began his wrestling career using the ring name of "Soldier Leavitt."

After the war, Leavitt embarked on a career in athletics. Although signed for a brief time (1919-20) with the "Brickley's Giants" football club, he concentrated most of his efforts toward the less lucrative field of professional wrestling. He competed in the ring for a time under the name "Hell's Kitchen Bill-Bill" (a "hillbilly" reference which was suggested to him by the writer Damon Runyon) but eventually settled on the moniker of "Stone Mountain".

Leavitt wrestled with limited success at first, and after an injury took a job as a police officer in Miami, Florida. It was here he met his wife, Doris Dean, who also became his manager. After her idea, he adopted the nickname "Man Mountain" and substituted the more Anglo-Saxon-sounding last name of Dean. At well over six feet in height and weighing in excess of 300 pounds, Dean was an imposing figure. To this he added a long, full beard as part of his ring persona. Dean was one of the first professional wrestlers to emphasize showmanship in the sport, and it worked to his advantage.

After a highly successful wrestling tour of Germany which had been booked by his wife, he was invited to take a job in the UK as stunt-double for Charles Laughton in the movie The Private Life of Henry VIII. This would be the beginning of a subsidiary movie career for Dean, who would appear in various roles in twelve other movies, playing himself in five of them. One of the movies in which he portrayed himself was the Joe E. Brown comedy "The Gladiator", a 1938 adaptation of Philip Gordon Wylie's 1930 novel Gladiator.

Meanwhile he continued a fairly successful wrestling career, participating altogether in 6,783 professional bouts and commanding fees upwards of $1,500 for each match. In 1937 he retired from the ring to a farm outside of Norcross, Georgia.

Dean ran for a seat in the Georgia House of Representatives in 1938 but withdrew his candidacy, citing discomfort with the political process. During World War II he again joined the Army despite his age, and finally left with the rank of master sergeant. Afterward he studied at the University of Georgia's school of journalism. He appeared as a guest on the December 29, 1944 episode of the radio program "It Pays to be Ignorant". During the program, broadcast from New York City, Dean gave his weight as 280 pounds (127 kg).

He died of a heart attack in his home in Norcross at the age of 63, and is buried in Marietta National Cemetery under a military marker bearing his birth name and an erroneous year of birth (1889). (If this year of birth is erroneous, then Leavitt died at age 61.)