Abstract: Although the Walton Family Foundation devotes some resources to traditional school districts, 80 percent of its education funding (some $50 million a year) supports charter schooling. This report documents how the foundation has been instrumental to the expansion of the charter school sector. The foundation has supported hundreds of new individual charter schools, a number of charter school management companies, an array of national, state, and local charter advocacy organizations, numerous technical-assistance organizations, and a wide range of charter school research. The foundation's charter school support has also led many others to fund the charter movement, including Donald Fisher, the founder of the Gap and an active charter school philanthropist who contributes substantially to the KIPP charter school network.