The duties of the Secretary of State’s office are divided among 21 departments employing approximately 4,000 people.

The office’s functions are described in the Illinois Constitution, mainly addressing the Secretary of State's duty to maintain official state records and the state seal. However, law and tradition have assigned many additional responsibilities to the office, which has one of the largest and most diverse collections of responsibilities of any of its counterparts nationwide.

From issuing driver’s licenses and registering vehicles, to promoting organ/tissue donation awareness, overseeing the Illinois State Library and administering the state's literacy efforts, the Secretary of State's office directly touches the lives of nearly everyone in Illinois.