William Haskell Alsup (born 1945) is a United States federal judge.
Alsup was born in Jackson, Mississippi. He received a B.S. from Mississippi State University in 1967. He received a J.D. from Harvard University in 1971. He received a M.P.P. from Harvard University's John F. Kennedy School of Government in 1971. He was a law clerk, Justice William O. Douglas, Supreme Court of the United States from 1971 to 1972. He was in private practice of law in San Francisco, CA from 1972 to 1978. He was an Assistant to U.S. Solicitor General, U.S. Department of Justice from 1978 to 1980. He was in private practice of law in San Francisco, CA from 1980 to 1998. He was a Special counsel, Antitrust Division, U.S. Department of Justice in 1998. He was in private practice of law in San Francisco, CA from 1998 to 1999.
Alsup was a federal judge to the United States District Court for the Northern District of California. Alsup was nominated by President Bill Clinton on March 24, 1999, to a seat vacated by Thelton Eugene Henderson. He was confirmed by the United States Senate on July 30, 1999, and received his commission on August 17, 1999.