Joseph Michael Nathan (born November 22, 1974 in Houston, Texas) is a Major League Baseball closer for the Minnesota Twins. He bats and throws right-handed, and stands at a height of 6 feet 4 inches (1.93 m). He started playing baseball as a shortstop in high school, and played the same position in college. However, he became a pitcher after the San Francisco Giants drafted him in 1995. After working his way through the minor leagues, he alternated between spots in the rotation and the bullpen. He spent a few seasons splitting time between the majors and the minors before having a breakout season as a relief pitcher in 2003. Nathan joined the Minnesota Twins in 2004 and became their closing pitcher. He continues to hold that position and is often regarded as one of the best closers in baseball.

Joe Nathan attended Pine Bush High School in Pine Bush, New York, where he played basketball and baseball and ran track. He graduated in 1992. However, only Division III colleges showed even minimal interest in having him play for their program. Nathan ended up playing college baseball at Stony Brook University as a result of his baseball coach and Stony Brook's coach having a history; Pine Bush assistant baseball coach Jeff Masionet and Stony Brook baseball coach Matt Senk played college baseball together at State University of New York at Cortland.

Nathan played college baseball as a shortstop at Division I SUNY Stony Brook. He became a two-time Academic All-American, and graduated as a member of the Golden Key International Honour Society. During his tenure there, professional baseball scouts began to notice his good arm and pitcher's body, and on a day where a game was rained out, "literally someone from every organization" came to watch him pitch. He was then drafted in the sixth round (159th overall) from the amateur draft by the San Francisco Giants in 1995, and signed on June 2, a day after being drafted. His college jersey number has since been retired, and he has been given the University Medal, the highest recognition given by the university. Nathan also played for the Fairfield Stallions in the New England Collegiate Baseball League in 1994.