William F. Rylaarsdam (born February 13, 1937) is an Associate Justice on the California Courts of Appeal, Fourth District, Division Three. He was appointed by Governor Pete Wilson and, after his confirmation, took the oath of office on April 10, 1995. He was retained by voters in the November 5, 2002 election.
Rylaarsdam graduated from the University of California at Berkeley in 1957 and went on to receive his law degree from Loyola Law School in 1964. In 1998, he received his Master of Laws degree from the University of Virginia School of Law. He is currently married with four children and seven grandchildren.
Rylaarsdam began his career in 1964 as an attorney practicing civil litigation. He was among counsel of record to the defendants in a landmark insurance bad faith case decided by the Supreme Court of California in 1973, in which the Court ruled that the implied covenant of good faith and fair dealing applies to all insurance, not just liability insurance.
He worked for various private firms in Los Angeles, Pasadena, and Newport Beach until 1985, when Governor George Deukmejian appointed him to the Los Angeles Superior Court. The next year, he was transferred to the Orange County Superior Court. He worked there until his appointment to the Fourth District, Division Three Court of Appeal in 1995.