John V. Roos is the Ambassador Extraordinary and Plenipotentiary of the United States of America to Japan.

In announcing Ambassador Roos’s selection, President Obama said, "A partnership between the United States and Japan is one of tremendous interest. The person who I thought could best do this is somebody with superb judgment, somebody with an outstanding intellect, somebody who is a very close friend of mine and a close advisor, somebody who has worked both in the private sector with cutting-edge technologies, but also is somebody who has a deep interest in public service. He is somebody who I'm confident is going to be able to help to strengthen both the regional and the global relationship between the United States and Japan." Ambassador Roos was sworn into office on August 16, 2009.

Since his arrival in Tokyo, Ambassador Roos has built relationships and established a rich and active dialogue with government leaders, businesspeople, media and students over the course of his travels across more than half of Japan's prefectures. In addition to addressing the security, economic, and global challenges that Japan and the United States face, Ambassador Roos has drawn a specific focus on areas of cooperation that include people to people connections, innovation and entrepreneurship, renewable energy, educational exchange, and trade issues. He also works closely with Japan on issues related to the Hague Convention. On August 6, 2010 he became the first U.S. official ever to attend the commemoration ceremony of the atomic bombing in Hiroshima.

Prior to his appointment, Ambassador Roos served as Chief Executive Officer at Wilson Sonsini Goodrich & Rosati, the leading law firm in the U.S. in the representation of technology, life sciences, and emerging growth companies. There he helped lead his firm during the waves of innovation in Silicon Valley, from the growth of software and communications, to the Internet Age and the emergence of biotechnology, to today's focus on clean technology and renewable energy.

Throughout his career, Ambassador Roos has been active in public service, serving on a public school board in California from 1991 to 1999 and in politics, where he worked on presidential campaigns for Walter Mondale, Bill Bradley and John Kerry before joining President Obama's campaign. Prior to becoming Ambassador to Japan, Ambassador Roos served on the Stanford School of Education Dean's Advisory Board and on the Law School Dean's Advisory Council. He was elected to membership in the Stanford Associates for his long-standing volunteer service to the University.

Ambassador Roos grew up in San Francisco and attended Stanford, where he graduated Phi Beta Kappa with Honors and Distinction, and Stanford Law School, earning his Juris Doctor in 1980, achieving Order of the Coif. He and his wife Susie have two children living in California, their daughter, Lauren, a nurse in the Neonatal Intensive Care Unit at Children's Hospital of Los Angeles, and their son, David, a freshman at Stanford.