In 1977, Jennings was arrested by federal agents for conspiracy and possession of cocaine with intent to distribute. A private courier warned the Drug Enforcement Administration about the package sent to Jennings by a New York colleague that contained 27 grams of cocaine. The DEA and the police searched Jennings's recording studio but found no evidence because, while they were waiting for a search warrant, Jennings disposed of the drug. The charges were later dropped and Jennings was released. The episode was recounted in Jennings's song "Don't You Think This Outlaw Bit's Done Got Outta Hand?"

Jennings first started with prescription amphetamines in the 1960s, but by the late 1970s had a full blow cocaine addiction. He reportedly spent up to $1,500 per day on cocaine, amassing more than $2.5 million worth of personal debt.

Between 1985 and 1995, The Highwaymen recorded three major label albums. They also starred together in the 1986 film Stagecoach.

He made a cameo appearance in the live-action children's film Follow That Bird, in which he plays a turkey farm truck driver who gives Sesame Street's Big Bird a lift. He also sings one of the film's songs, entitled "Ain't No Road Too Long".

Jennings was married four times and had six children.

Waylon is perhaps as frank a country autobiography as has ever been written. It graphically traces Jennings' career from hardscrabble poverty in West Texas to teenage bassist for Buddy Holly to Nashville rebel to Outlaw star to cocaine addict to redemption.

"There weren't another other way to be
For lovable losers and no account boozers
And honky tonk heroes like me"

Jennings was portrayed by his son Shooter, though the younger man's shoulder-length hair and beard made him look little like his father appeared at the time (circa 1966) when Cash and Jennings shared an apartment outside Nashville. Shooter also plays his father in a scene set several years previously; for this scene he did cut his hair and shave, heightening the resemblance to Waylon.

In October 2001, Jennings was finally inducted into the Country Music Hall of Fame. In one final act of defiance, he did not show up to accept the award and opted instead to send his son Buddy Dean Jennings in his place.