How smart do you have to be to be a FBI agent?

Smart enough to pass an extensive mental health examination, which would include an IQ test. The average persons IQ is approximately 100, while Genius begins at 140. Though genius is not necessary, an IQ of approximately 120 (gifted) would most likely be within the range necessary to fulfill the duties and obligations of an employee of the FBI.

Other factors, such as honesty, temperament, emotional stability would also be considered in the psychological exam.