A regulatory agency is a common name for an agency that has been delegated authority by Congress to issue rules or regulations, to issue licenses, to establish rates, or to undertake a combination of these actions. Traditionally, when people referred to a "regulatory agency" they usually had in mind one of the multi-member, "independent" regulatory boards or commissions, like the FCC or FERC, that issue licenses and otherwise regulate the economic status of a particular industry. (See Independent Regulatory Agency.)

In recent years Congress has given more and more regulatory authority to executive branch departments and single-headed agencies, such as OSHA in Labor, NHTSA in Transportation, and EPA. Today there are approximately 100 regulatory agencies of the Federal government.