Milton Friedman (/ˈfriːdmən/ ^ⓘ; July 31, 1912 – November 16, 2006) was an American economist and statistician who received the 1976 Nobel Memorial Prize in Economic Sciences for his research on consumption analysis, monetary history and theory and the complexity of stabilization policy. With George Stigler, Friedman was among the intellectual leaders of the Chicago school of economics, a neoclassical school of economic thought associated with the faculty at the University of Chicago that rejected Keynesianism in favor of monetarism before shifting their focus to new classical macroeconomics in the mid-1970s. Several students, young professors and academics who were recruited or mentored by Friedman at Chicago went on to become leading economists, including Gary Becker (Nobel Prize 1992), Robert Fogel (Nobel Prize 1993), and Robert Lucas Jr.(Nobel Prize 1995)

Friedman's challenges to what he called "naive Keynesian theory" began with his interpretation of consumption, which tracks how consumers spend. He introduced a theory which would later become part of mainstream economics and he was among the first to propagate the theory of consumption smoothing. During the 1960s, he became the main advocate opposing both Marxist and Keynesian government and economic policies, and described his approach (along with mainstream economics) as using "Keynesian language and apparatus" yet rejecting its initial conclusions. He theorized that there existed a natural rate of unemployment and argued that unemployment below this rate would cause inflation to accelerate. He argued that the Phillips curve was in the long run vertical at the "natural rate" and predicted what would come to be known as stagflation. Friedman promoted a macroeconomic viewpoint known as monetarism and argued that a steady, small expansion of the money supply was the preferred policy, as compared to rapid and unexpected changes. His ideas concerning monetary policy, taxation, privatization, and deregulation influenced government policies, especially during the 1980s. His monetary theory influenced the Federal Reserve's monetary policy in response to the 2008 financial crisis.

After retiring from the University of Chicago in 1977, and becoming emeritus professor in economics in 1983, Friedman served as an advisor to Republican U.S. president Ronald Reagan and Conservative British prime minister Margaret Thatcher. His political philosophy extolled the virtues of a free market economic system with minimal government intervention in social matters. In his 1962 book Capitalism and Freedom, Friedman advocated policies such as a volunteer military, freely floating exchange rates, abolition of medical licenses, a negative income tax, school vouchers, and opposition to the war on drugs and support for drug liberalization policies. His support for school choice led him to found the Friedman Foundation for Educational Choice, later renamed EdChoice.

Friedman's works cover a broad range of economic topics and public policy issues. His books and essays have had global influence, including in former communist states. A 2011 survey of economists commissioned by the EJW ranked Friedman as the second-most popular economist of the 20th century, following only John Maynard Keynes. Upon his death, The Economist described him as "the most influential economist of the second half of the 20th century ... possibly of all of it".

Friedman was born in Brooklyn, New York City, on July 31, 1912. His parents, Sára Ethel (née Landau) and Jenő Saul Friedman, were Jewish working-class immigrants from Beregszász in Carpathian Ruthenia, Kingdom of Hungary (now Berehove in Ukraine). They emigrated to the United States in their early teens. They both worked as dry goods merchants. Milton was the youngest of four children and only son. Shortly after his birth, the family relocated to Rahway, New Jersey. Friedman's father died during Friedman's senior year of high school, leaving Friedman and two older sisters to care for their mother.

In his early teens, Friedman was injured in a car accident, which scarred his upper lip. A talented student and an avid reader, Friedman graduated from Rahway High School in 1928, just before his 16th birthday. He was the first in his family to attend a university. Friedman was awarded a competitive scholarship to Rutgers University and graduated in 1932.

Friedman initially intended to become an actuary or mathematician, however, the state of the economy, which was at this point in a depression, convinced him to become an economist. He was offered two scholarships to do graduate work, one in mathematics at Brown University and the other in economics at the University of Chicago. Friedman chose the latter, earning a Master of Arts degree in 1933. He was strongly influenced by Jacob Viner, Frank Knight, and Henry Simons. Friedman met his future wife, economist Rose Director, while at the University of Chicago. Friedman was also the student of Friedrich Hayek.

During the 1933–1934 academic year, he had a fellowship at Columbia University, where he studied statistics with statistician and economist Harold Hotelling. He was back in Chicago for the 1934–1935 academic year, working as a research assistant for Henry Schultz, who was then working on Theory and Measurement of Demand.