Walter J. Haas, also known as Wally Haas, is an American businessman and a son of Walter A. Haas Jr. and Evelyn D. Haas, founders of the Evelyn and Walter Haas, Jr. Fund (also known as the Haas Jr. Fund), a private foundation that provides grants primarily to left-of-center activist groups.
Walter J. Haas has contributed towards various politicians and political action committees (PAC), most notably he donated $1,000 to George W. Bush in 1999, $1,000 to the Democratic Party-aligned PAC to the Future in 2001, and $2,300 to the presidential campaign of former New York Mayor Rudolph W. Giuliani (R) in 2007. 
Walter J. Haas is a director and the current board chairman of the Evelyn and Walter Haas, Jr. Fund, a private foundation that provides grants primarily to left-of-center activist groups, with a focus on supporting liberal expansionist immigration policy, LGBT interests, education, and organizations in the San Francisco Bay area. To date, the Fund has awarded more than $640 million in grants, including approximately $22 million in 2020. Haas joined the board of directors for the foundation in 1972, and formerly was co-chair with his mother Evelyn D. Haas from 1996 until her passing in 2010.   
Haas is a former board president of the Walter and Elise Haas Fund, one of several private foundations associated with members of the Haas family that have been involved in the operation of Levi Strauss & Co. 
He is also chairman of the board of Coaching Corps. Cathy Cha, the president and a former vice president of programs at the Evelyn and Walter Haas, Jr. Fund, also sits on the board of directors for Coaching Corps.  
Haas has also sat on the board of directors of the Golden Gate National Parks Conservancy, Marin Country Day School, and San Francisco Urban School. 
Haas was also the executive vice-president of the Oakland A’s, a baseball team formerly owned by the Haas family. He worked as the team’s executive vice-president from 1980 to 1987, chief operating officer from 1988 until 1989, and CEO and chairman from 1993 until 1995. Haas also sat on the board of directors of Levi Strauss & Co, the company in which his father Walter A. Haas Jr made his fortune as CEO. Walter J. Haas also served as a member of the company’s Corporate Ethics and Social Responsibility Committee from 1995 until 2006.