There are nine justices: one Chief Justice and eight associate justices.
William H. Rehnquist, entered on duty September 26, 1986,
John Paul Stevens
Sandra Day O'Connor
Antonin Scalia
Anthony M. Kennedy
David H. Souter
Clarence Thomas
Ruth Bader Ginsburg
Stephen G. Breyer
Retired Associate Justices
Byron R. White
Harry A. Blackmun
Lewis F. Powell, Jr.
Additional information on the Supreme Court Justices is available, courtesy of Cornell University Law School.