Joe Wambaugh, Jr. is a best-selling American writer known for his fictional and nonfictional accounts of police work in the United States. Several of his early novels were set in Los Angeles, and its surroundings, and featured Los Angeles police officers as protagonists. He has been nominated for four Edgar Awards (winning three), and was named a Grand Master by the Mystery Writers of America.

The son of a police officer, Wambaugh was born in East Pittsburgh, Pennsylvania. He joined the United States Marine Corps at age 17 (an element he works into several of his novels) and married at 18. Wambaugh is of Irish and German descent.

Wambaugh received an associate of arts degree from Chaffey College and joined the Los Angeles Police Department in 1960. He served for 14 years, rising through the ranks from patrolman to detective sergeant. He also attended California State University, Los Angeles, where he earned bachelor of arts and master of arts degrees.

Wambaugh's perspective on police work led to his first novel, The New Centurions, which was published early in 1971 to critical acclaim and popular success, while Wambaugh was still a detective. He later quipped that suspects would ask for his autograph.

Soon turning to writing full time, Wambaugh was prolific and popular starting in the 1970s. He mixed writing novels (The Blue Knight, The Choirboys, The Black Marble) with nonfiction accounts of crime and detection (true crime): The Onion Field. His later books included The Glitter Dome (a TV-movie adaptation that starred James Garner and John Lithgow), The Delta Star, and Lines and Shadows.