The John D. and Catherine T. MacArthur Foundation is one of the nation’s largest independent philanthropic foundations, dedicated to building a more just, verdant, and peaceful world. Established in 1978 through the legacy of John D. and Catherine T. MacArthur, the Foundation supports creative people, effective institutions, and influential networks that are advancing solutions to some of the world’s most pressing social and environmental challenges.
Through programmatic grantmaking, impact investing, strategic partnerships, convening power, and collaborations at scale, MacArthur strives toward transformative change on some of the world’s most pressing social issues, including the existential threats of climate change, criminal justice reform, revitalizing local news in the United States, expanding who creates, uses, and benefits from artificial intelligence, strengthening Native communities, and empowering young people in Nigeria.
In addition to their award programs, MacArthur Fellows, and 100&Change, the Foundation continues its historic commitments to the role of journalism in a responsible and responsive democracy and to the strength and vitality of their headquarters city, Chicago. The Foundation also works to strengthen ecosystems of people, organizations and networks working on deploying catalytic capital, strengthening the philanthropic sector and addressing the social impacts of technology.
Across its portfolio, the Foundation approaches its work with urgency, intellectual rigor, adaptability, and a commitment to continuous learning, leveraging grants, impact investments, communications, convenings, contracts, and partnerships to achieve measurable and lasting impact.
Since its founding, MacArthur has awarded more than $9.19 billion through grants and impact investments to approximately 11,000 organizations and individuals and has supported work in 119 countries. Headquartered in Chicago, the Foundation maintains offices in India and Nigeria. As of December 31, 2025, MacArthur’s assets totaled approximately $9.9 billion. In 2025 alone, the Foundation provided approximately $561.6 million in grants and program-related investments and committed an estimated $647 million in charitable spending, reflecting its continued commitment to investing boldly in solutions that create meaningful and enduring change.