P. J. Proby (born James Marcus Smith; November 6, 1938) is an American singer, songwriter, and actor.

Proby recorded the singles "Hold Me", "Somewhere", and "Maria". In 2008, EMI released the greatest hits album Best of the EMI Years 1961–1972. He still writes and records on his own independent record label, Select Records, and performs in the UK in Sixties concerts.

By the time Proby left school, he had already wanted a career "in the movies" and moved to California to become an actor and recording artist. Given the stage name Jett Powers by Hollywood agents Gabey, Lutz, Heller, and Loeb, he took acting and singing lessons and played small roles in films. Two singles, "Go, Girl, Go" and "Loud Perfume" appeared on two small independent record labels. In 1960, songwriter Sharon Sheeley convinced him to adopt the stage name P. J. Proby, the name of a former boyfriend from high school, and secured Proby an audition for Dick Glasser of Liberty Records. It was a success, and Proby signed with the label and the music publisher Metric Music. After a number of unsuccessful singles, in 1962 Proby began writing songs and recording demos for artists such as Elvis Presley, Bobby Vee, and Johnny Burnette, who had his final UK chart success with the song "Clown Shoes", credited to Proby's real name.