Dantonio began his coaching career at Ohio University, where he was a graduate assistant. In 1981, he made his first stop in the Big Ten Conference when he moved on to Purdue University as a graduate assistant. He spent two years, in 1983 and 1984, as a graduate assistant at Ohio State University under head coach Earle Bruce. In 1986, he began a five-year stint on Jim Tressel's staff at Youngstown State University as a defensive secondary coach. In 1990, Dantonio led the Penguins' defense to an 11–0 record and a No. 2 ranking nationally. Glen Mason hired Dantonio in 1991 to be the defensive secondary coach for the Kansas Jayhawks. When Nick Saban was hired at Michigan State in 1995, he hired Dantonio to join his staff in East Lansing where he remained even after Saban left for LSU. After Bobby Williams was named head coach in 1999 following Saban's departure, Dantonio was promoted to associate head coach where he remained through the 2000 season.
