Barry Morris Goldwater (January 2, 1909 – May 29, 1998) was an American politician and major general in the Air Force Reserve who served as a United States senator from 1953 to 1965 and 1969 to 1987, and was the Republican Party's nominee for president in 1964.

Goldwater was born in Phoenix, Arizona, where he helped manage his family's department store. During World War II, he flew aircraft between the U.S. and India. After the war, Goldwater served in the Phoenix City Council. In 1952, he was elected to the U.S. Senate, where he rejected the legacy of the New Deal and, along with the conservative coalition, fought against the New Deal coalition. Goldwater also challenged his party's moderate to liberal wing on policy issues. He supported the Civil Rights Acts of 1957 and 1960 and the 24th Amendment to the U.S. Constitution but opposed the Civil Rights Act of 1964, disagreeing with Title II and Title VII. In the 1964 U.S. presidential election, Goldwater mobilized a large conservative constituency to win the Republican nomination, but then lost the general election to incumbent Democratic president Lyndon B. Johnson in a landslide.

Goldwater returned to the Senate in 1969 and specialized in defense and foreign policy. He successfully urged president Richard Nixon to resign in 1974 when evidence of a cover-up in the Watergate scandal became overwhelming and impeachment was imminent. In 1986, he oversaw passage of the Goldwater–Nichols Act, which strengthened civilian authority in the U.S. Department of Defense. Near the end of his career, Goldwater's views on social and cultural issues grew increasingly libertarian.

Many political pundits and historians believe he laid the foundation for the conservative revolution to follow as the grassroots organization and conservative takeover of the Republican Party began a long-term realignment in American politics, which helped to bring about the presidency of Ronald Reagan in the 1980s. He also had a substantial impact on the American libertarian movement. After leaving the Senate, Goldwater became supportive of environmental protection, gay rights, including military service and adoption rights for same-sex couples, abortion rights, and the legalization of marijuana.

Goldwater was born on January 2, 1909, in Phoenix, Arizona, in what was then the Arizona Territory, the son of Baron M. Goldwater and his wife, Hattie Josephine "JoJo" Williams. Goldwater long believed that he was born on January 1, 1909, and thus works published during his career list this as his date of birth; however, in his later years, he discovered documentation revealing that he was actually born at 3 a.m. on January 2. His father's family founded Goldwater's Department Store, a leading upscale department store in Phoenix. Goldwater's paternal grandfather, Michel Goldwasser, a Polish Jew, was born in 1821 in Konin, then part of Congress Poland. He emigrated to London following the Revolutions of 1848. Soon after arriving in London, Michel anglicized his name to Michael Goldwater. Michel married Sarah Nathan, a member of an English-Jewish family, in the Great Synagogue of London.

The Goldwaters later emigrated to the United States, first arriving in San Francisco, California, before finally settling in the Arizona Territory, where Michael Goldwater opened a small department store that was later taken over and expanded by his three sons, Henry, Baron, and Morris. Morris Goldwater (1852–1939) was an Arizona territorial and state legislator, mayor of Prescott, Arizona, delegate to the Arizona Constitutional Convention, and later President of the Arizona State Senate.

Goldwater's father was Jewish, but Goldwater was raised in his mother's Episcopal faith. Hattie Williams came from an established New England family that included the theologian Roger Williams, of Rhode Island. Goldwater's parents were married in an Episcopal church in Phoenix; for his entire life, Goldwater was an Episcopalian, though on rare occasions he referred to himself as Jewish. While he did not often attend church, he stated that "If a man acts in a religious way, an ethical way, then he's really a religious man—and it doesn't have a lot to do with how often he gets inside a church." His first cousin was Julius Goldwater, a convert to Buddhism and Jodo Shinshu priest who assisted interned Japanese Americans during World War II.

After performing poorly academically as a high school freshman, Goldwater's parents sent him to Staunton Military Academy in Staunton, Virginia, where he played varsity football, basketball, track, and swimming; was senior class treasurer; and attained the rank of captain. He graduated from the academy in 1928 and enrolled at the University of Arizona, but dropped out after one year. Barry Goldwater is the most recent non-college graduate to be the nominee of a major political party in a presidential election. Goldwater entered the family's business around the time of his father's death, in 1930. Six years later, he took over the department store, though he was not particularly enthused about running the business.