The suspect was not immediately identified by police, which set up a media staging area near the school.
“Run, Hide, Fight. Secure yourself immediately,” the university said on Twitter shortly before 6 p.m. (2200GMT)
The school said on its website the campus was on lockdown and that students and staff should “remain in a safe location.”
A spokeswoman for Charlotte-Mecklenberg Police Department confirmed there had been an active shooter at the university but declined to give any further information.
According to its website the University of North Carolina at Charlotte enrolls more than 26,500 students and employees 3,000 faculty and staff.