Billy Childish (born Steven John Hamper; 1 December 1959) is an English painter, author, poet, photographer, film maker, singer and guitarist. Since the late 1970s, Childish has been prolific in creating music, writing and visual art. He has led and played in bands including the Thee Milkshakes, Thee Headcoats, and the Musicians of the British Empire, primarily working in the genres of garage rock, punk and surf and releasing more than 100 albums.

He is a consistent advocate for amateurism and free emotional expression. Childish co-founded the Stuckism art movement with Charles Thomson in 1999, which he left in 2001. Since then a new evaluation of Childish's standing in the art world has been under way, culminating with the publication of a critical study of Childish's working practice by the artist and writer Neal Brown, with an introduction by Peter Doig, which describes Childish as "one of the most outstanding, and often misunderstood, figures on the British art scene". He is a visiting lecturer at Rochester Independent College. In July 2014 Childish was awarded an honorary Doctor of Arts Degree from the University of Kent.

He is known for his explicit and prolific work – he has detailed his love life and childhood sexual abuse, notably in his early poetry and the novels My Fault (1996), Notebooks of a Naked Youth (1997), Sex Crimes of the Futcher (2004) – The Idiocy of Idears (2007), and in several of his songs, notably in the instrumental "Paedophile" (1992) (featuring a photograph of the man who sexually abused him on the front cover) and "Every Bit of Me" (1993). From 1981 until 1987 Childish had a relationship with artist Tracey Emin.

Thirty years after Childish's first musical releases with Thee Milkshakes and Thee Mighty Caesars, a crop of lo-fi, surf rock and punk groups with psychedelic subtexts has surfaced referencing the aesthetic established by Childish in both their band names and in various aspects of their sonic aesthetic: Thee Oh Sees, Thee Open Sex, Thee Tsunamis, Thee Dang Dangs, and many others.