Rex Daniel Grossman III (born August 23, 1980 in Bloomington, Indiana) is an American football quarterback of the National Football League, who is currently an NFL free agent. He graduated from Bloomington High School South and attended the University of Florida on an athletic scholarship. Grossman led the Florida Gators to the 2000 SEC Championship, the 2001 Sugar Bowl, the 2002 Orange Bowl and the 2003 Outback Bowl. He was the runner-up for the 2001 Heisman Trophy. Grossman began his professional career with the Chicago Bears as the twenty-second overall selection in the 2003 NFL Draft, but spent most of his first three seasons sidelined with injuries. He completed his first full season in 2006, leading the Bears to a National Football Conference Championship, and helping the team score the second most points in the league. He eventually lost his starting job three weeks into the 2007 season, and primarily served as the team's backup quarterback.

Rex Grossman was born to Daniel and Maureen Grossman in Bloomington, Indiana. Under the motivation and guidance of his father, Daniel, Grossman began playing football at an early age in grade school. He originally started his football career as a running back. Despite his success as a running back, Grossman’s mother, Maureen, asked his coach to convert him to a quarterback while he was in the sixth grade.

He attended Bloomington South High School, where he threw 97 touchdowns for 7,518 yards. Grossman threw 44 touchdown passes during his senior year, including a game where he threw six and two games where he threw four. His senior season reached its pinnacle on November 28, 1998, when he led his team to a 35-14 5A championship title over Homestead High School. Grossman threw five touchdowns for 216 yards, setting a state record for most touchdowns thrown in a championship game.