Elmer Wayne Henley Jr. (born May 9, 1956) is an American serial killer incarcerated in the Texas Department of Criminal Justice (TDCJ) system. Henley was convicted in 1974^: 219 for his role as a participant in a series of murders known as the Houston Mass Murders in which a minimum of 28 teenage boys and young men were abducted, tortured, raped and murdered by Dean Corll between 1970 and 1973. Henley and David Owen Brooks (Corll's other teenage accomplice), together and individually, lured many of the victims to Corll's home. Henley, then 17 years old, shot Corll dead on August 8, 1973.

Henley is serving six consecutive terms of 99 years for his involvement in the Houston Mass Murders, which at the time were characterized as "the deadliest case of serial murders in American history".