Butler was selected by the Packers in the second round of the 1990 NFL draft. He played in 181 games, earned a Super Bowl ring, for Super Bowl XXXI, following the 1996 season, was selected as an All-Pro five times and was selected to the Pro Bowl four times (1993, 1996, 1997, and 1998). He was named to the 1990s NFL All Decade Team, by the Pro Football Hall of Fame, and was later inducted into the Green Bay Packers Hall of Fame, in 2007.

During his 12 seasons with the Packers, he recorded 953 tackles, 38 interceptions, 553 return yards, 12 fumble recoveries, 3 defensive touchdowns and 20½ sacks. He led or tied for the team lead in interceptions in five different seasons. He was the first defensive back in NFL history to gain entrance in the 20 Sack/20 Interception Club.

A broken shoulder blade sustained while making a tackle against the Atlanta Falcons in the 2001 season forced him into retirement just before the 2002 season.