A public utility is an entity that provides the general public with essential goods and services such as electricity, natural gas, energy, water, sewer, heat, telecommunications (telephone, fiber optic or broadband internet), railroad, and rail transit.

Public utilities (goods and services) are often provided by a public utility corporation that is essentially given a monopoly over the provision of the good or service in a certain geographic area—and exemption from antitrust and unfair competition laws—in exchange for certain governmental restrictions and regulations. Public utility companies are often regulated by a governmental Public Utility Commission (PUC).

The laws and rules that govern public utilities are usually located in state or federal statutes—depending on whether the utility is regulated by the state or federal government. For example, many states have a public utilities code—sometimes called a public utility regulatory act—or provide for public utility corporations and their regulation in the state administrative code. The Federal Energy Regulatory Commission (FERC) is one example of a PUC at the federal level.

In New York State, public utilities are regulated entities that provide essential services such as electricity, gas, water, and telecommunications to the public. These utilities are typically granted a monopoly within a certain geographic area in exchange for agreeing to be regulated by the state. The primary regulatory body in New York is the New York State Public Service Commission (PSC), which oversees and regulates the state's electric, gas, water, and telecommunications utilities. The PSC sets rates, ensures adequate service, and protects consumer interests. It operates under the New York Public Service Law, which outlines the commission's powers and duties. Additionally, the Federal Energy Regulatory Commission (FERC) regulates aspects of the energy industry at the federal level, including interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas pricing, and oil pipeline rates. The division of regulatory authority between state and federal bodies depends on the scope and nature of the utility's operations, with interstate activities typically falling under federal jurisdiction.