Peter Thacher Grauer (born October 1945) is an American businessman, entrepreneur, and philanthropist who has been a pivotal figure at Bloomberg L.P. since joining its board in October 1996. He served as chairman of the board from 2001 to 2023 and transitioned to executive chairman thereafter, having joined the company full-time in March 2002. Prior to Bloomberg, he founded DLJ Merchant Banking Partners, a prominent investment firm, where he built expertise in private equity and merchant banking. He maintains a professional partnership with Michael Bloomberg and has co-founded initiatives with investments in media, finance, and private equity through firms like PWP Growth Equity. Additionally, Grauer serves as the lead independent director of DaVita Inc., a major healthcare company. His career reflects deep involvement in high-profile business networks, leveraging Wall Street experience to influence finance, technology, and media industries. Beyond corporate roles, Grauer's philanthropy includes significant donations to institutions like the New York Public Library and support for education, arts, social causes, and criminal justice reform, underscoring his commitment to public good.