After serving as a graduate assistant coach at Oregon, Turner was an assistant coach for the USC Trojans from 1976 to 1984. From 1985 to 1990, he was an assistant with the Los Angeles Rams.

Turner was the offensive coordinator with the Dallas Cowboys on Jimmy Johnson's staff when Dallas won back to back Super Bowls in 1992 and 1993. Turner got much of the credit for not only their success, but for helping shape quarterback Troy Aikman into a Hall of Fame player.

In 1994, following his success with the Cowboys, Turner was hired as the head coach of the Washington Redskins. In 1996 Turner led the Redskins to a 7-1 start and made the playoffs in 1999.

On February 19, 2007 Turner was hired as the new head coach of the San Diego Chargers. Turner led the Chargers to their first playoff victory since 1994 with a victory over the Tennessee Titans, followed by a second playoff win over the Indianapolis Colts.

On September 11, 2011, Turner recorded his 100 regular season win as a head coach in the NFL.