Chalmers played his first three years of high school basketball at Notre Dame-Bishop Gibbons in Schenectady, New York.

Chalmers attended Xavier University, where he played college basketball for four years as an undergraduate and later as a graduate student.

He played in the Greek A1 league with AEK Athens BC from November 2005 to February 2006, when he then joined TAU Cerámica of the Spanish ACB.

After the Hawks waived him before the regular season began, Chalmers signed with Dinamo Banco di Sardegna Sassari of the Italian second division in December 2006.

[11] Chalmers began his coaching career in 2017 as a video coordinator of the Orlando Magic, becoming an associate coach/player development two years later.

[12] Lionel's cousin, Mario Chalmers, formerly of the Kansas Jayhawks, was picked in the second round of the 2008 NBA draft by the Minnesota Timberwolves.