Leonard J. Kosmalski (born November 21, 1951) is a retired American basketball player.

He played collegiately at the University of Tennessee and professionally for the National Basketball Association's Kansas City Kings.

Kosmalski, a 7-foot center from Maple Heights High School in Ohio, was a three-year starter for the Tennessee Volunteers and a three-time first team All-Southeastern Conference pick and was a starter on the Vols' 1972 SEC championship team.

[1] Kosmalski played parts of two seasons for the Kings, averaging 1.4 points and 1.9 rebounds in 76 games.

[1] His son Landry Kosmalski is the current head basketball coach at Swarthmore College.