William Joseph Martin (formerly known as Poppy Z. Brite) is an American author born on May 25, 1967. Initially gaining fame in the gothic horror genre during the early 1990s, he published a series of successful novels and short story collections. Martin is best known for his novels Lost Souls (1992), Drawing Blood (1993), and Exquisite Corpse (1996).

Martin's later work transitioned into the genre of dark comedy, with numerous stories set in the New Orleans restaurant world. Although Martin's novels are typically standalone, they may feature recurring characters from previous novels and short stories. His works often include openly bisexual and gay characters, reflecting his own experiences and identity.

Born as Melissa Ann Brite, Martin, who is now known as Billy Martin, has discussed his experiences with gender dysphoria and gender identity issues. Identifying primarily as a homosexual male, he began taking testosterone injections in 2011.

Martin lived in Chapel Hill, North Carolina, and Athens, Georgia before returning to New Orleans in 1993. He is a fan of UNC basketball, a sometimes season ticket holder for the NBA, and has a particular fondness for his hometown football team, the New Orleans Saints.