[1] Gill was born in Chicago and attended Rich Central High School in Olympia Fields, Illinois.

Graduating in 1986 as a senior, he led Rich Central to a second-place finish in the IHSA class AA state boys basketball tournament.

He had a tough time as a rookie trying to fit into the Hornets rotation, alongside already established back-court teammates Muggsy Bogues and Rex Chapman.

After the 1991 addition of Larry Johnson and departure of Rex Chapman to the Washington Bullets, Gill had a breakthrough year in the 1991–92 season by averaging 20.5 points, 5.1 rebounds and 4.2 assists per game, while shooting 46.7% from the field.

The SuperSonics, who also added Detlef Schrempf that summer, had a team led by Gary Payton and Shawn Kemp.

Gill returned to Charlotte for the 1995–96 season after being traded there for Hersey Hawkins and David Wingate and in January 1996 the Hornets traded Gill and Khalid Reeves to the New Jersey Nets for Kenny Anderson, who became the team's starting point guard while Bogues sat out with a knee injury that limited him to just six games for the entire season.

From 1996 to 2001, Gill played for the Nets, scoring a career-high 41 points on January 14, 1997,[2] helping the team reach the 1998 playoffs, and leading the league in steals in 1998–99.

[6] In 2017, Gill was signed as a free agent in the BIG3 basketball league by Power to take the place of Corey Maggette after he suffered an injury during the season.