Leonido Fregoli was an Italian actor and illusionist, born on June 2, 1867, in Turin, Italy. He is best known for his remarkable ability to change his appearance quickly, which led to the term "Fregoli delusion," a psychological condition where a person believes that different people are actually the same individual in disguise. Fregoli's performances captivated audiences in the early 20th century, showcasing his talent for rapid costume changes and impersonations. Fregoli's influence extended beyond the stage, impacting the fields of psychology and popular culture. His name is often associated with the concept of identity and perception, as seen in various works of literature and film. The Fregoli delusion is still studied today, highlighting the connection between his artistic legacy and psychological phenomena.