I. Lewis "Scooter" Libby, born Irving Lewis Libby Jr. on August 22, 1950, in New Haven, Connecticut, is an American attorney, author, and political adviser known for his significant role in the neoconservative movement and U.S. foreign policy. A Yale-educated historian specializing in Russian studies and a Columbia Law School graduate, he served as Chief of Staff and Assistant for National Security Affairs to Vice President Dick Cheney from 2001 to 2005. In this capacity, he was a prominent architect advocating for the 2003 invasion of Iraq and regime change based on intelligence concerning weapons of mass destruction. Earlier in his career, Libby held positions in the Reagan and George H.W. Bush administrations, including Principal Deputy Under Secretary of Defense for Policy, and served as Executive Director of the Project for the New American Century, a think tank promoting assertive U.S. foreign policy. He also worked at private law firms such as Latham & Watkins and Williams & Connolly.

Libby's tenure ended amid the CIA leak scandal known as the Valerie Plame affair, in which he was indicted in 2005 on charges of perjury, obstruction of justice, and making false statements during the investigation into the unauthorized disclosure of CIA operative Valerie Plame's identity. He was convicted in 2007 on four of five counts, including obstruction of justice and perjury, and sentenced to 30 months in prison and a $250,000 fine. President George W. Bush commuted his sentence, sparing him from incarceration, and later, President Donald Trump granted Libby a full pardon on April 13, 2018. The case provoked controversy over executive clemency for political allies, with critics asserting that Libby's actions undermined national security, while supporters viewed the prosecution as politically motivated.

After leaving government service, Libby became Senior Vice President at the Hudson Institute, maintaining influence within conservative think tanks and foreign policy circles. He is also a novelist, having published "The Apprentice" in 2004 under the pseudonym Jeff Poor. Libby is married to Harriet Laurie Libby, a nonprofit executive, and they have two children. His career reflects a blend of legal expertise, policy influence, and literary activity but remains overshadowed by legal controversies that highlighted tensions in intelligence handling and accountability. Libby continues to be a divisive figure associated with neoconservative foreign policy debates and connected to influential figures such as Paul Wolfowitz, his Yale classmate, and Richard Perle.