Sir David Alan Walker (born 31 December 1939) is a British banker and former chairman of Barclays. He was chairman of Morgan Stanley International from 1995 to 2001, and 2004 to 2005, and remains a senior advisor. Walker was previously Assistant Secretary at the Treasury (1974–77), chairman of the Securities and Investments Board (1988–92), executive director for finance and industry at the Bank of England (1989–95) and deputy chairman of Lloyds TSB (1992–94). In 1994 he also joined the Washington-based financial advisory body, the Group of Thirty.
In 2007, Walker was commissioned by the UK private equity industry to produce guidelines for disclosure and transparency in private equity. On 9 February 2009, he was appointed to lead a government enquiry into banks' corporate governance; the appointment was criticised. On 9 August 2012 he was appointed Chairman of Barclays effective 1 November.
On 1 July 2015, Sir David Walker was appointed to global investment manager, Winton Capital Group, as its non-executive Chairman to support the Group’s ambition of becoming a global institutional asset-management group.
Walker was educated at Chesterfield School and Queens' College, Cambridge (MA, hon. fellow 1989; double first, economics). He married Isobel Cooper in 1963; they have one son and two daughters. Walker was knighted in 1991.
Walker joined HM Treasury in 1961, and was private secretary to the joint permanent secretary from 1964–66. He served on the staff of the International Monetary Fund in Washington from 1970–73, and was assistant secretary in HM Treasury from 1973–77. Walker joined the Bank of England as chief adviser and chief of the economic intelligence department in 1977 and was a director from 1981–93 (1988–93 as a non-executive). He chaired Johnson Matthey Bankers (later Minories Finance) from 1985–88, and was president of the Old Cestrefeldians' Society from 1986–88. Walker held positions with the SIB from 1988–92 and the Agricultural Mortgage Corporation from 1993–94, and was deputy chair of Lloyds Bank from 1992–94. He was a director at Morgan Stanley from 1994–97, executive chair of Morgan Stanley Group (Europe)—later Morgan Stanley Dean Witter (Europe)—from 1994–2000, chair of Morgan Stanley International from 1995–2000 and on the management board of Morgan Stanley Dean Witter from 1997–2000.