The Office of the Comptroller of the Currency (OCC) is an independent bureau within the United States Department of the Treasury that was established by the National Currency Act of 1863 and serves to charter, regulate, and supervise all national banks and federal thrift institutions and the federally licensed branches and agencies of foreign banks in the United States.

The head of the agency, the comptroller of the currency, is Jonathan V. Gould, who took office on July 15, 2025.

The OCC is one of the United States' federal banking regulators, with primary prudential authority over all national banks. There are two other federal regulators, the Federal Deposit Insurance Corporation (FDIC) and the Federal Reserve. The agency is headquartered in Washington, D.C. with four district offices located in New York City, Chicago, Dallas and Denver. It is an independent bureau of the United States Department of the Treasury. The official head of the agency is the comptroller of the currency, who is appointed to a five-year term by the president with the consent of the Senate.

The agency's budget is not congressionally appropriated, being paid for by assessment fees levied on regulated banks.

The OCC supervises national banks, federal savings associations, and federal branches and agencies of foreign banks to ensure that they operate safely and soundly, provide fair access to financial services, treat customers fairly, and comply with applicable laws and regulations.

The OCC regulates and supervises about 1,200 national banks, federally-licensed savings associations, and federally-licensed branches of foreign banks in the United States, accounting for more than two-thirds of the total assets of all U.S. commercial banks (as of September 30, 2020).

In Cuomo v. Clearing House Association, L. L. C. 557 U.S. 519 (2009), the Court clarified its decision in Watters, stating that federal banking regulations did not preempt the ability of states to enforce their own fair-lending laws, as "'general supervision and control' and 'oversight' are worlds apart from law enforcement", and therefore states retain law enforcement powers but have restricted "visitorial" powers over national banks (i.e., the right to examine the affairs of a corporation).

In July 2007, the OCC launched HelpWithMyBank.gov to assist customers of national banks and provide answers to national banking questions.

On July 10, 2020, the OCC announced the launch of Project REACh. REACh stands for Roundtable for Economic Access and Change, and the project brings together leaders from the banking industry, national civil rights organizations, business, and technology to reduce specific barriers that prevent full, equal, and fair participation in the nation's economy.