Davis attended Iowa State from 1996 to 1999. He holds the current ISU record for most number of career rushing attempts (823). He finished his Cyclone career as the second all-time leading rusher and number of all-purpose yardage (behind his brother, Troy) in school history with 3,763 yards and 5,008 yards. As a sophomore, Davis rushed for a career-high 261 yards in a loss against Kansas. In his senior season, Davis led the Big 12 in rushing yards (1,388). He also ranks seventh on the all-time Iowa State career rushing touchdown list with 26.