Billy Cox is an American bassist. He is best known for his work with Jimi Hendrix, with whom he formed the R&B outfit the King Kasuals; he later joined Hendrix's band Gypsys, Suns, and Rainbows in 1969 until Hendrix's death in 1970. He has released albums including Nitro Function, Last Gypsy Standing, Old School Blue Blues, and Unfiltered. Cox's most popular songs include Amazing Grace, The Night Ain't Got No Eyes, and 13th Hour. He has appeared in films such as Jimi Hendrix, Blue Wild Angel: Live At the Isle of Wight, and Jimi Hendrix Experience: Electric Church - Atlanta Pop Festival.