Stewart Abercrombie Baker (born July 17, 1947) was the first Assistant Secretary (acting as Under Secretary-equivalent) for Policy at the United States Department of Homeland Security under the Presidency of George W. Bush.[1][2]

Baker is the former General Counsel of the National Security Agency (1992–1994) and author of the book, The Limits of Trust: Cryptography, Governments, and Electronic Commerce (1998), and other publications and articles on electronic commerce and international trade. Earlier in his career, Baker was law clerk to John Paul Stevens, Supreme Court from 1977 to 1978. He also clerked for Frank M. Coffin, United States Court of Appeals, First Circuit (1976–1977) and Shirley Hufstedler, US Court of Appeals, Ninth Circuit (1975).[1][2] He was in private practice with the Washington, DC-based law firm Steptoe & Johnson LLP from 1981 to 1992 and again from 1994 to 2005.