James Robert Magnuson (August 18, 1946 – May 30, 1991) was a Major League Baseball pitcher who played in 1970 and 1971 with the Chicago White Sox and in 1973 with the New York Yankees. He batted right and threw left-handed. Magnuson had a 2–7 record in 36 career games.

Magnuson was born in Marinette, Wisconsin, the oldest of five children. His parents were Harry J. and Florence I. Magnuson of Marinette. An alumnus of the University of Wisconsin–Oshkosh, Magnuson was married with two children. He died of alcohol poisoning in Green Bay, Wisconsin in 1991.