Mr. Ryan was raised in San Francisco by immigrant parents.  He attended Saint Ignatius College Preparatory, earned a Bachelor of Arts degree in History from Dartmouth College, and received his Juris Doctor from the University of San Francisco School of Law. Mr. Ryan began his legal career in California as a Prosecutor with the Alameda County District Attorney's Office.  While in the District Attorney's office he handled a variety of cases, including homicides and violent gang prosecutions. He was serving as a member of the Violent Gang Suppression Unit when Governor Pete Wilson appointed him in 1996 to serve as a Judge on the San Francisco Municipal Court.  In 1998, he was overwhelmingly elected to the court by the voters of San Francisco and in 1999 he became a member of the San Francisco Superior Court. Mr. Ryan was serving as  the Presiding Judge, Criminal Division, for the San Francisco Superior Court when President Bush nominated him to be the United States Attorney for the Northen District of California.

During his career as a lawyer and judge,  Mr. Ryan has served both the administration of justice and the greater community in many different ways.  In 1998 he was recognized by the San Francisco Trial Lawyers' Association as the Municipal Court Trial Judge of the Year. Additionally, Mr. Ryan was appointed by the Chief Justice of the California Supreme Court to serve on the Judicial Council's Executive Legislative Action Network; he was appointed by the Governing Committee of the California Center for Judicial Education and Research to the Criminal Law Planning Committee of the California Continuing Judicial Studies Program; he was appointed by the Presiding Judge for the Courts to the Adult Probation Department's Oversight Committee; he served as a member of the Executive Committee of the San Francisco Superior Court; he served as a member of the Executive Committee of the University of San Francisco School of Law's American Inn of Courts; he served as a member of the University of San Francisco's Law Society Board of Governors; he is a member of the Board of Trustees for the Schools of the Sacred Heart in San Francisco; and he has served as a faculty member for the University of San Francisco School of Law Intensive Trial Advocacy Program for many years.  Mr. Ryan has also been invited to lecture on the law to various groups, including the San Francisco Police Department's Police Academy, and for other California judges through the California Center for Judicial Education and Research.

Mr. Ryan supervises one of the largest United States Attorney's offices in the country. The Northern District of California was established in 1851, the year following the admission of California as a state in the Union.  Mr. Ryan supervises a staff of 217 people, including 107 Assistant United States Attorneys, and manages an office budget of nearly $25 million.  The Northern District of California reflects the diversity and dynamism that California is known for. The District encompasses fifteen counties, and has a population base of nearly 7.5 million people.  It  includes the metropolitan areas of San Francisco, Oakland, and San Jose, as well as the Silicon Valley, and rural counties such as Humboldt and Del Norte.  The Northern District of California is home to the nation's first Computer Hacking and Intellectual Property Unit (CHIP), which is the model for the country.  Mr. Ryan serves as the Core City United States Attorney for the Pacific Region of the Organized Crime Drug Enforcement Task Force(OCDETF), which covers the largest geographic area within the OCDETF program. In further recognition of the national importance of this jurisdiction,  Mr. Ryan has been selected to serve on President Bush's Corporate Fraud Task Force, and he has been appointed by Attorney General John Ashcroft to serve on the Attorney General 's Subcommittees for Controlled Substances and Terrorism and National Security. Mr. Ryan also serves as a Board member for  the Northern California High Intensity Drug Trafficking Area working group.