Joel Irwin Klein (born October 25, 1946) is an American lawyer and education executive renowned for his leadership in public education and antitrust enforcement. He served as Chancellor of the New York City Department of Education (New York City Schools Chancellor) from 2002 to 2011 (until 2010 per some sources) under Mayor Michael Bloomberg, managing the largest public school system in the United States. During his tenure, Klein implemented sweeping reforms including school closures, expansion of charter schools, and performance-based accountability measures, which sparked both praise for innovation and criticism for centralization and teacher union conflicts. Prior to this role, he was Assistant Attorney General for the Antitrust Division at the U.S. Department of Justice from 1996 to 2000 under President Bill Clinton, where he oversaw significant cases such as the Microsoft antitrust lawsuit and mergers in the telecommunications sector. After stepping down as chancellor, Klein transitioned to the private sector, initially joining News Corporation as Executive Vice President and later becoming CEO of its education division, Amplify. He has also served as executive vice president at HBO. Klein has since worked as a lawyer, education consultant, and advisor on policy and business matters, contributing to various initiatives aimed at education reform and technology integration in learning. His career reflects a blend of legal expertise and public service, influencing networks in government, media, and education sectors.