The award was announced in San Francisco on Wednesday at a meeting of the state Judicial Council, the governing body of the state court system.
The honor is known as the Bernard E. Witkin Amicus Curiae Award and is given each year to individuals outside the judiciary "for outstanding contributions to the courts of California."
Council spokeswoman Lynn Holton said California Chief Justice Ronald George and Administrative Director of the Courts William Vickrey will present the award later this year.
The council said that in 1987, Fox worked with San Mateo County Superior Court judges to create one of the first programs in the state to resolve some felony cases at an early stage, in advance of a preliminary hearing.
In 1995, the district attorney helped to develop the San Mateo County Drug Court, which provides intensive treatment for drug offenders.
Two years ago, Fox was a founding member of a group of judges and probation officers who developed a mental health court for repeat criminal offenders in San Mateo County Superior Court. The court provides treatment and intensive probation supervision as an alternative to incarceration.
Fox was president of the National District Attorneys Association in 2007-2008 and of the California District Attorneys Association in 1995. He also serves on the Judicial Council's Criminal Law Advisory Committee.
The 2009 Witkin Award will also be given to Riverside County Chief Public Defender Gary Windom.