Ron Zook played college football as a defensive back for Miami University, and graduated with a bachelor's degree in 1976. Zook immediately began coaching football, beginning at Orrville High School in Orrville, Ohio in 1976. In 1978, Zook moved to coaching collegiately, beginning at Murray State University. Through the 1980s, Zook held coaching positions at a number of schools, including University of Cincinnati, University of Kansas, University of Tennessee, Virginia Tech, and Ohio State University.

Beginning in 1991, Zook served as defensive coordinator for three seasons at the University of Florida under head coach Steve Spurrier. After the 1993 season, Spurrier reassigned Zook to be the special teams coordinator, a move considered by many to be a demotion. Nonetheless, in 1995 Spurrier added the title of associate head coach to Zook's position.

In 1996, Zook left Florida to coach in the National Football League. Zook served three seasons as special teams coach for the Pittsburgh Steelers, and was the defensive backs coach for the Kansas City Chiefs in 1999. In the 2000 and 2001 seasons, Zook was the defensive coordinator for the New Orleans Saints.

In 2002, Spurrier resigned his position with Florida to become the head coach of the Washington Redskins of the NFL, and Florida hired Zook to be his replacement. Spurrier had coached twelve seasons at Florida, and had taken a school with historically limited success on the football field to become a national power. Expectations at Florida were high, and Zook's hiring was not considered a popular one by followers of Florida football. In fact, one fan started a website, fireronzook.com, within a day of Zook's hiring, and the web site gained national media attention.

Zook was the head coach at Florida for three seasons. In those three seasons, the Gators compiled records of 8-5 (in 2002), 8-5 (in 2003) and 7-5 (in 2004). While achieving some modest success, Zook's record fell well short of the expectations at Florida. In his three years, the Gators lost more games in their home stadium (Ben Hill Griffin Stadium) than in the 12 seasons under Spurrier. Zook was fired before the end of the 2004 season after a loss to the Mississippi State Bulldogs, who had a 1-5 record prior to the game. Zook finished the regular season but declined to coach the Gators in their bowl game, having already accepted the Illinois position. After the 2004 season, Zook was replaced as Florida's head coach by Urban Meyer.

Though not highly regarded by many Gator fans, Zook did have some big achievements over his 3 seasons. He bested the Florida State Seminoles in Tallahassee on their newly-christened "Bobby Bowden Field" in his final game as head coach. Also, he had winning records against many Southeastern Conference foes such as the Georgia Bulldogs (he went 2-1), and the Auburn Tigers (1-0). In addition, Zook coached the Gators to a victory over the BCS National Champion LSU Tigers in 2003, the only loss for LSU that season.

In 2005, the University of Illinois hired Zook to replace Ron Turner as the head coach of the Fighting Illini football team. Zook inherited a program which had finished 1-11 in 2003 and 3-8 in 2004, including Big Ten records of 0-8 and 1-7, respectively. In Zook's inaugural season of 2005, Illinois finished with an overall record of 2-9, and a record of 0-8 in Big Ten games.

Despite his team's struggles in his first year, Zook has improved the ability of Illinois to recruit top football talent. According to one source, the 2006 recruiting class is one of the 30 best in college football [1]. The recruiting class includes Isiah Williams of Chicago Vocational High School, considered to be one of the top six quarterback recruits in the country.