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.