A company is a legal entity that represents an association of legal persons with a specific, shared objective, such as the earning of profit or the benefit of society. Depending on jurisdiction, companies can take on various forms, such as voluntary associations, nonprofit organizations, business entities, financial entities, banks, and educational institutions. Across jurisdictions, companies have generally evolved to have certain common legal features, including separate legal personality, limited liability, transferable shares, investor ownership, and a managerial hierarchy.

Depending on jurisdiction, the term "company" may or may not be synonymous with corporation, partnership, firm and society. Companies are governed by company law, which is also known as corporate law in some jurisdictions. Incorporated companies are created by and registered with the state, whereas unincorporated companies are not.

When a company closes, it may need to be liquidated to avoid further legal obligations. Companies may associate and collectively register themselves as new companies known as corporate groups, collections of parent and subsidiary corporations.

English law recognised long ago that a corporation would have separate legal personality, also known as corporate personality or juridical personhood. In 1612, Sir Edward Coke remarked in the Case of Sutton's Hospital,

the Corporation itself is onely in abstracto, and resteth onely in intendment and consideration of the Law; for a Corporation aggregate of many is invisible, immortal, & resteth only in intendment and consideration of the Law; and therefore it cannot have predecessor nor successor. They may not commit treason, nor be outlawed, nor excommunicate, for they have no souls, neither can they appear in person, but by Attorney. A Corporation aggregate of many cannot do fealty, for an invisible body cannot be in person, nor can swear, it is not subject to imbecilities, or death of the natural, body, and divers other cases.

In 1776, Adam Smith wrote in the Wealth of Nations that mass corporate activity could not match private entrepreneurship, because people in charge of "other people's money" would not exercise as much care as they would with their own.

In 1843, William Gladstone took chairmanship of a Parliamentary Committee on Joint Stock Companies, which led to the Joint Stock Companies Act 1844.

At the end of the 19th century in the United States, the law allowed for the concentration of wealth and power in the hands of a few people, or a single person. In response, the Sherman Antitrust Act of 1890 was created to break up big business conglomerates, and the Clayton Act of 1914 gave the government power to halt mergers and acquisitions that could damage the public interest. By the end of the First World War, it was increasingly perceived that ordinary people had little voice compared to the "financial oligarchy" of bankers and industrial magnates. In particular, employees lacked voice compared to shareholders, but plans for a post-war "industrial democracy" (giving employees votes for investing their labor) did not become widespread.