Count Five was an American garage rock band formed in San Jose, California, in 1964. The band was founded by lead guitarist John "Mouse" Michalski and bassist Roy Chaney, who were friends from Pioneer High School. They initially played in a surf rock group called the Citations before evolving into Count Five, influenced by the British Invasion. The band's lineup included John "Sean" Byrne on rhythm guitar and lead vocals, Kenn Ellner on tambourine and harmonica, and Craig "Butch" Atkinson on drums.

Count Five is best known for their hit single "Psychotic Reaction," which became a cornerstone of garage rock. The song, influenced by bands like the Standells and the Yardbirds, was released by Double Shot Records and peaked at number five on the U.S. charts in 1966. Despite their initial success, Count Five struggled to maintain their popularity and disbanded in 1969.

The band was known for wearing Count Dracula-style capes during live performances. "Psychotic Reaction" was later included in the 1972 compilation album Nuggets: Original Artyfacts from the First Psychedelic Era, 1965–1968, which introduced the song to a new generation. The band briefly reunited in 1987 for a concert in Santa Clara, California, which was released as a live album. Count Five remains a notable example of a one-hit-wonder from the garage rock era.