Lem Barney attended Jackson State University (Mississippi) where he was a three-time All-Southwestern Conference star with 26 career interceptions.

Barney was a second round draft choice in 1967. He was named 1967's defensive Rookie of the Year, and went on to be selected to seven Pro Bowls. During his time in the NFL, Barney had 56 career interceptions, and also gained over 1000 yards each returning kickoffs and punts. He was selected to the Pro Football Hall of Fame in 1992.

Both Barney and Lions teammate Mel Farr befriended Motown star Marvin Gaye, when Gaye unsuccessfully tried out for the Lions in 1970. Barney and Farr sing background vocals on Gaye's classic 1971 song "What's Going On". Lem Barney also had a role in the film The Black Six.