From 1818 until June 30, 1958, state banks and trust departments were regulated by the Auditor of Public Accounts. Initially, the Auditor of Public Accounts was appointed by the General Assembly for a four year term, in 1833 the term was reduced to two years; and under the revisions to the 1848 constitution, the office became a popularly elected one with elected officials serving four year terms.

On July 1, 1958, the responsibility for regulating trust departments and trust companies was transferred to a newly created agency within the executive branch of government named the Department of Financial Institutions. The supervision of state banks remained with the Banking Division of the Auditor of Public Accounts until January 1, 1959, following a vote of the people at a referendum held on November 4, 1958.

On January 1, 1967, the office of Commissioner of Banks and Trust Companies was formed following a referendum of the people and the responsibility of the supervision of banks and trust companies was transferred to this new agency.

On July 1, 1996, the Office of the Commissioner of Savings and Residential Finance was merged with and into the Commissioner of Banks and Trust Companies and the agency's name was changed to the Office of Banks and Real Estate.

On July 1, 2004, the Office of Banks and Real Estate, the Department of Financial Institutions, the Department of Insurance, and the Department of Professional Regulation consolidated into an  agency named the Illinois Department of Financial and Professional Regulation (IDFPR) pursuant to the provisions of Executive Order Number 6 (2004).  Each of the former agencies became a division of the new agency.

On July 1, 2009, the Division of Insurance separated from IDFPR and became the Department of Insurance pursuant to the provisions of Exectuve Order Number 4 (2009).

The following is a listing of the chief banking regulators and the departments responsible for regulating State banks in Illinois history.