Clarence Thomas is an American lawyer and jurist who serves as an associate justice of the Supreme Court of the United States. He was nominated by President George H. W. Bush to succeed Thurgood Marshall and has served since 1991. After Marshall, Thomas is the second African American to serve on the Supreme Court and has been its longest-serving member since Anthony Kennedy's retirement in 2018. Since Stephen Breyer's retirement in 2022, he is also the Court's oldest member.

An associate justice of the Supreme Court of the United States is a justice of the Supreme Court of the United States, other than the chief justice of the United States. The number of associate justices is eight, as set by the Judiciary Act of 1869.