Karl Stuart Nelson (born June 14, 1960) is a former American football offensive tackle who played professionally in the National Football League (NFL) for the New York Giants. He was a member of the 1986 Giants team that won Super Bowl XXI. He missed the 1987 season due to Hodgkin's disease. Nelson played college football at Iowa State University. He also served as a commentator on Giants radio broadcasts.

Nelson currently^[when?] resides with his wife, Inga, in Northern New Jersey where he works in the financial industry, and is an active advocate for various charities. His primary charity is Adopt-a-Soldier Platoon.