Nicholas John Grunzweig Jr. (July 21, 1918 – February 10, 2007) was an American professional basketball player. He played for the Tri-Cities Blackhawks in the National Basketball League during the 1946–47 season and averaged 2.8 points per game. Grunzweig served in the United States Army in both World War II and the Korean War, and spent the majority of his professional career in the military. After retirement from the military, he moved to Iowa where he worked for the Department of Human Services until retiring in 1979.