This document provides a history of the thriller genre from the 1920s to present day. It describes how Alfred Hitchcock pioneered the genre with silent films in the 1920s-1930s. Psychological thrillers emerged in the 1940s-1950s due to films like Gaslight and The Spiral Staircase. Iconic directors like Hitchcock and films like Psycho further developed the genre in the 1960s. Spy thrillers increased in popularity during the 1960s as well. The thriller genre continued to evolve with films in the 1970s-1980s featuring more graphic content. Recent thrillers from the 1990s onward have utilized special effects and featured famous source material and franchises.