The Green Revolution, or the Third Agricultural Revolution, was a period during which technology transfer initiatives resulted in a significant increase in crop yields. These changes in agriculture initially emerged in developed countries in the early 20th century and subsequently spread globally until the late 1980s. In the late 1960s, farmers began incorporating new technologies, including high-yielding varieties of cereals, particularly dwarf wheat and rice, and the widespread use of chemical fertilizers (to produce their high yields, the new seeds require far more fertilizer than traditional varieties), pesticides, and controlled irrigation.

At the same time, newer methods of cultivation, including mechanization, were adopted, often as a package of practices to replace traditional agricultural technology. This was often in conjunction with loans conditional on policy changes being made by the developing nations adopting them, such as privatizing fertilizer manufacture and distribution.

Both the Ford Foundation and the Rockefeller Foundation were heavily involved in its initial development in Mexico. A key leader was agricultural scientist Norman Borlaug, the "Father of the Green Revolution", who received the Nobel Peace Prize in 1970. He is credited with saving over a billion people from starvation. Another important scientific figure was Yuan Longping, whose work on hybrid rice varieties is credited with saving at least as many lives. The basic approach was the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers. As crops began to reach the maximum improvement possible through selective breeding, genetic modification technologies were developed to allow for continued efforts.

Studies show that the Green Revolution contributed to widespread eradication of poverty, averted hunger for millions, raised incomes, increased greenhouse gas emissions, reduced land use for agriculture, and contributed to declines in infant mortality.

The term "Green Revolution" was first used by William S. Gaud, the administrator of the U.S. Agency for International Development (USAID), in a speech on 8 March 1968. He noted the spread of the new technologies as:

These and other developments in the field of agriculture contain the makings of a new revolution. It is not a violent Red Revolution like that of the Soviets, nor is it a White Revolution like that of the Shah of Iran. I call it the Green Revolution.

Mexico has been called the 'birthplace' and 'burial ground' of the Green Revolution. It began with great promise and it has been argued that "during the twentieth century two 'revolutions' transformed rural Mexico: the Mexican Revolution (1910–1920) and the Green Revolution (1940–1970)."

The genesis of the Green Revolution was a lengthy visit in 1940 by U.S. Vice President-elect Henry A. Wallace, who had served as U.S. Secretary of Agriculture during President Franklin Roosevelt's first two terms, and before government service, had founded a company, Pioneer Hi-Bred International, that had revolutionized the hybridization of seed corn to greatly increase crop yields. He became appalled at the meager corn yields in Mexico, where 80 percent of the people lived off the land, and a Mexican farmer had to work as much as 500 hours to produce a single bushel of corn, about 50 times longer than the typical Iowa farmer planting hybrid seed. Wallace persuaded the Rockefeller Foundation to fund an agricultural station in Mexico to hybridize corn and wheat for arid climates, and to lead it, he hired a young Iowa agronomist named Norman Borlaug.