William Rehnquist, American lawyer and jurist, 16th Chief Justice of the United States (d. 2005)
William Hubbs Rehnquist ( REN-kwist; October 1, 1924 – September 3, 2005) was an American lawyer and jurist who served on the Supreme Court of the United States for 33 years, first as an associate justice from 1972 to 1986, then as the 16th chief justice from 1986 until his death in 2005. Considered a conservative, Rehnquist favored a conception of federalism that emphasized the Tenth Amendment's reservation of powers to the states. Under this view of federalism, the Court, for the first time since the 1930s, struck down an act of Congress as exceeding its power under the Commerce Clause.

Rehnquist grew up in Milwaukee, Wisconsin, and served in the U.S. Army Air Forces during the final years of World War II. After the war's end in 1945, he studied political science at Stanford University and Harvard University, then attended Stanford Law School, where he was an editor of the Stanford Law Review and graduated first in his class. Rehnquist clerked for Justice Robert H. Jackson during the Supreme Court's 1952–53 term, then entered private practice in Phoenix, Arizona. Rehnquist served as a legal adviser for Republican presidential nominee Barry Goldwater in the 1964 election, and in 1969 President Richard Nixon appointed him Assistant Attorney General of the Office of Legal Counsel. In 1971, Nixon nominated Rehnquist to succeed Associate Justice John Marshall Harlan II, and the U.S. Senate confirmed him that year. During his confirmation hearings, Rehnquist was criticized for allegedly opposing the Supreme Court's decision in Brown v. Board of Education. Whether he committed perjury during the hearings is debated by historians. Rehnquist quickly established himself as the Burger Court's most conservative member. In 1986, President Ronald Reagan nominated Rehnquist to succeed retiring Chief Justice Warren Burger, and the Senate confirmed him.

Rehnquist served as Chief Justice for nearly 19 years, making him the fourth-longest-serving Chief and the eighth-longest-serving Justice. He became an intellectual and social leader of the Rehnquist Court, earning respect even from the justices who frequently opposed his opinions. Though he remained a member of the conservative wing of the court, Associate Justices Antonin Scalia and Clarence Thomas were often regarded as more conservative. As Chief Justice, Rehnquist presided over the impeachment trial of President Bill Clinton.

Rehnquist wrote the majority opinions in United States v. Lopez (1995) and United States v. Morrison (2000), holding in both cases that Congress had exceeded its power under the Commerce Clause. He opposed Roe v. Wade and continued to argue that Roe had been incorrectly decided in Planned Parenthood v. Casey. In Bush v. Gore, he voted with the court's majority to end the Florida recount in the 2000 presidential election.