The William and Flora Hewlett Foundation, commonly known as the Hewlett Foundation, is a major American private philanthropic foundation and one of the largest in the United States. Headquartered in Menlo Park, California, it was established in 1966 by William Redington Hewlett, co-founder of Hewlett-Packard, his wife Flora Lamson Hewlett, and their eldest son Walter B. Hewlett. The foundation was created through the Hewlett family's personal generosity, with initial funding derived from Hewlett-Packard's success in the technology sector. It focuses on funding programs in education, environmental protection, global development, and democratic governance, as well as addressing population issues. The foundation aims to build an inclusive society where people, communities, and the planet can flourish by supporting nonprofits, research institutions, think tanks, policy developers, and advocacy groups aligned with progressive and evidence-based approaches. Notable efforts include combating climate change through policy and innovation, improving educational outcomes domestically and internationally, and strengthening democratic institutions by promoting electoral integrity and civic engagement. As of December 31, 2024, the foundation holds assets valued at approximately $13.9 billion. In 2023, it reported revenue of about $602 million and expenses nearing $700 million, primarily allocated to grantmaking in philanthropy, voluntarism, education, and human services, with a focus on California and broader U.S. initiatives. The Hewlett Foundation maintains transparency through a grants database and financial disclosures while positioning itself as a nonpartisan supporter of the public good, though critics have occasionally accused it of exerting undue influence on progressive environmental and political agendas.