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 Missouri, public utilities are regulated entities that provide essential services such as electricity, gas, water, sewer, telecommunications, and transportation to the public. These utilities are typically granted a monopoly within a certain geographic area in exchange for agreeing to governmental oversight and regulation. The regulation is aimed at ensuring that the services are provided fairly, with reasonable rates, and are accessible to all segments of the population. The Missouri Public Service Commission (PSC) is the state regulatory body responsible for overseeing public utilities in Missouri. It ensures that customers receive adequate services at fair prices while allowing the utility companies the opportunity to earn a reasonable return on their investments. The PSC sets rates, hears customer complaints, and regulates the operations of the utilities. At the federal level, agencies like the Federal Energy Regulatory Commission (FERC) regulate aspects of utility services that cross state lines, such as electricity transmission and natural gas pipelines. State statutes, such as those found in the Missouri Revised Statutes, and regulations in the state administrative code provide the legal framework for the operation and regulation of public utilities in Missouri.