William Sydney Fisher (born 1958) is an American investor, hedge fund manager, and philanthropist. He has been a director of Gap Inc. since 2009, and the founder and chief executive officer of Manzanita Capital Limited. The son of Gap Inc. founders Donald Fisher and Doris F. Fisher, William Fisher has been involved with the company as a board member or employee for nearly 30 years. As of January 2018, Fisher has a net worth of US$1.85 billion.