For J. Edgar Hoover, secrets were a way of life. As the first director of the FBI, it was part of his everyday work life to create and keep secrets, with regards to his professional career. However, to Hoover, secrets were also one of the necessary evils of his personal life.

Decades have passed since his death in 1972, but the rumors surrounding the controversial personal and professional life of J. Edgar Hoover continue. Until the age of 40, Hoover lived with his mother, whom he had a somewhat irrational obsession with (even following her death). He was also a lifelong bachelor, never marrying and never fathering any children. As part of his incomparably controversial career, Hoover spent an untold amount of personal and professional time gathering information about the sexual orientation and activities of countless numbers of politicians, government leaders, co-workers, rivals, friends, and enemies. He spent an inordinate amount of time trying to ensnare civil rights leader Martin Luther King, Jr. in a scandal for his alleged infidelities, but the media refused to report it. He also devoted a great deal of energy monitoring the purported lesbian affairs of Eleanor Roosevelt, and the heterosexual affairs of John F. Kennedy, in supposedly-failed attempts at blackmail.

There is a great deal of contradiction regarding whether or not Hoover was truly homosexual. Some historians claim his homosexuality is definite, citing his decades-long, incomparably-close relationship with associate and fellow-FBI agent, Clyde Tolson. Following Hoover's death in 1972, Tolson inherited more than $551,000 and moved into Hoover's home, after accepting the U.S. flag draped across the coffin at Hoover's funeral. The men were frequently seen together, sharing meals, attending social events and night clubs, and even vacationing together (without other companions). Both men spent their entire lives unmarried and childless, despite rumors about Hoover's alleged romantic entanglements with actress Dorothy Lamour in the 1930s and 40s, as well as Lela Rogers (mother of Ginger Rogers) in the following decade. If he was gay, Hoover did a rather remarkable job of covering it up with seemingly heterosexual behavior, and vehement, vocal opposition to homosexuality (as during the Lavender Scare).

However, there were also rumors of Hoover being a cross-dresser. In fact, rumors of people seeing J. Edgar Hoover in a dress continue to this very day. Anthony Summers, a journalist who wrote Official and Confidential: The Secret Life of J. Edgar Hoover (1993) quoted Susan Rosenstiel (a 'society divorcee') as claiming she saw him cross-dressing at homosexual parties in the 1950s. Summers also alleged the Mafia had some sort of 'blackmail material' on Hoover (purportedly related to his cross-dressing) which led to his reluctance to acknowledge or investigate both the Mafia's existence and activities. Despite the continued rumors, there has never been any confirmation of the cross-dressing allegations. Famous author Truman Capote (himself a homosexual) is quoted as admitting to be more interested in making Hoover angry (by spreading rumors) than finding out whether or not the rumors were actually true.