Earl Warren (March 19, 1891 – July 9, 1974) was an American attorney, politician, and jurist who served as the 14th Chief Justice of the United States from 1953 to 1969. The Warren Court presided over a major shift in American constitutional jurisprudence, which has been recognized by many as a "Constitutional Revolution" in the liberal direction, with Warren writing the majority opinions in landmark cases such as Brown v. Board of Education (1954), Reynolds v. Sims (1964), Miranda v. Arizona (1966), and Loving v. Virginia (1967). Warren also led the Warren Commission, a presidential commission that investigated the 1963 assassination of President John F. Kennedy. He also served as Governor of California from 1943 to 1953, and is the last chief justice to have served in an elected office before nomination to the Supreme Court. Warren is generally considered to be one of the most influential Supreme Court justices and political leaders in the history of the United States.

Warren was born in 1891 in Los Angeles and was raised in Bakersfield, California. After graduating from the University of California, Berkeley School of Law, he began a legal career in Oakland. He was hired as a deputy district attorney for Alameda County in 1920 and was appointed district attorney in 1925. He emerged as a leader of the state Republican Party and won election as the Attorney General of California in 1938. In that position he supported, and was a firm proponent of, the forced removal and internment of over 100,000 Japanese Americans during World War II. In the 1942 California gubernatorial election, Warren defeated incumbent Democratic governor Culbert Olson. He also served as the 30th Governor of California from 1943 until 1953, presiding over a period of major growth for the state. Warren is the only governor of California to be elected for three consecutive terms.

Warren served as Thomas E. Dewey's running mate in the 1948 presidential election, but Dewey lost the election to incumbent President Harry S. Truman. Warren sought the Republican nomination in the 1952 presidential election, but the party nominated General Dwight D. Eisenhower. After Eisenhower won election as president, he appointed Warren as Chief Justice. A series of rulings made by the Warren Court in the 1950s led directly to the decline of McCarthyism. Warren helped arrange a unanimous decision in Brown v. Board of Education (1954), which ruled that racial segregation in public schools was unconstitutional. After Brown, the Warren Court continued to issue rulings that helped bring an end to the segregationist Jim Crow laws that were prevalent throughout the Southern United States. In Heart of Atlanta Motel, Inc. v. United States (1964), the Court upheld the Civil Rights Act of 1964, a federal law that prohibits racial segregation in public institutions and public accommodations.

In the 1960s, the Warren Court handed down several landmark rulings that significantly transformed criminal procedure, redistricting, and other areas of the law. Many of the Court's decisions incorporated the Bill of Rights, making the protections of the Bill of Rights apply to state and local governments. Gideon v. Wainwright (1963) established a criminal defendant's right to an attorney in felony cases, and Miranda v. Arizona (1966) required police officers to give what became known as the Miranda warning to suspects taken into police custody that advises them of their constitutional protections. Reynolds v. Sims (1964) established that all state legislative districts must be of roughly equal population size, while the Court's holding in Wesberry v. Sanders (1964) required equal populations for congressional districts, thus achieving "one man, one vote" in the United States. Schmerber v. California (1966) established that forced extraction of a blood sample is not compelled testimony, illuminating the limits on the protections of the 4th and 5th Amendments and Warden v. Hayden (1967) dramatically expanded the rights of police to seize evidence with a search warrant, reversing the mere evidence rule. Furthermore, Griswold v. Connecticut (1965) established a constitutional right to privacy and struck down a state law that restricted access to contraceptives, and Loving v. Virginia (1967) struck down state anti-miscegenation laws, which had banned or otherwise regulated interracial marriage. Warren announced his retirement in 1968 and was succeeded by Appellate Judge Warren E. Burger in 1969. The Warren Court's rulings have received criticism, but have received widespread support and acclamation from both liberals and conservatives. As yet, few of the Court's decisions have been overturned.