A minimum wage is the lowest hourly, daily or monthly wage that employers may legally pay to employees or workers. First enacted in Australia and New Zealand in the late nineteenth century, minimum wage laws are now in force in more than 90% of all countries.

The history of minimum wage laws begins in 1896, when New Zealand established arbitration boards with the Industrial Conciliation and Arbitration Act. Also in 1896 in Victoria, Australia, an amendment to the Factories Act provided for the creation of a wages board. The wages board did not set a universal minimum wage, but set basic wages for six industries that were considered to pay low wages. First enacted as a four-year experiment, the wages board was renewed in 1900 and made permanent in 1904. By that time it covered 150 different industries. By 1902, other Australian states, such as New South Wales and Western Australia, had also formed wages boards.

In 1907, the Harvester decision was handed down in Australia. It established a 'living wage' for a man, his wife and two children to "live in frugal comfort." In 1907 Ernest Aves was sent by the British Secretary of State for the Home Department to investigate the results of the minimum wage laws in Australia and New Zealand. In part as a result of his report, Winston Churchill, then president of the Board of Trade, introduced the Trade Boards Act on March 24, 1909. It became law in October of that year, and went into effect in January of 1910. In 1912, the state of Massachusetts, United States, set minimum wages for women and children. In the United States, statutory minimum wages were first introduced nationally in 1938. In addition to the federal minimum wage, nearly all states within the United States have their own minimum wage laws with the exception of South Carolina, Tennessee, Alabama, Mississippi and Louisiana. In the 1960s, minimum wage laws were introduced into Latin America as part of the Alliance for Progress; however these minimum wages were, and are, low.

In the European Union, 18 out of 27 member states currently have national minimum wages. Many countries, such as Norway, Sweden, Finland, Denmark, Switzerland, Germany, Austria, Italy, and Cyprus have no minimum wage laws, but rely on employer groups and trade unions to set minimum earnings through collective bargaining.

Many supporters of the minimum wage assert that it is a matter of social justice that helps reduce exploitation and ensures workers can afford what they consider to be basic necessities. In the economics profession, however - and particularly among American economists - opinions of the minimum wage tend to be less favorable. A 2000 survey by Dan Fuller and Doris Geide-Stevenson reports that of a sample of 308 American Economic Association economists, 45.6% fully agreed with the statement, "a minimum wage increases unemployment among young and unskilled workers", 27.9% agreed under certain conditions, and 26.5% disagreed.