Billy Boy may refer to:

• "Billy Boy", a traditional folk song
• Billy Boy (1954 film), a 1954 animated short cartoon by Metro-Goldwyn-Mayer and directed by Tex Avery
• Billy Boy (2017 film), a 2017 film directed by Bradley Buecker
• Billy Boy (wrestler) (born 1977), Mexican Luchador
• Billy Boy (novel), a golf-themed novel by Bud Shrake
• "Billy Boys", a loyalist song from Glasgow, Scotland
• Billy Boy Arnold (born 1935), American blues harmonica player, singer and songwriter
• Billy Boy on Poison, an American rock and roll band from Los Angeles
• BillyBoy* (born 1960), jewelry designer
• "Willy Use a Billy... Boy", a 1995 song recorded by German eurodance project E-Rotic