WASHINGTON, DC, May 5, 2026 — The ONE Campaign, a global advocacy organization advancing economic opportunity and health across Africa, today announced Ambassador Mark Green as its next President and CEO, effective May 25, Africa Day.

Green succeeds Dr. Ndidi Okonkwo Nwuneli, who will remain on ONE’s Board of Directors and serve in a pivotal advisory role as well as Chair of a new board committee to support the organization’s growing presence across Africa. She is stepping down from the CEO role to be closer to her family in Nigeria and to scale her entrepreneurial ventures in agribusiness, philanthropy and social innovation. She will support a seamless leadership transition.

“Ndidi deftly led ONE through a period of transformation, strengthening our strategy, systems and leadership while deepening our impact across Africa,” said Tom Freston, Chair of ONE’s Board of Directors. “We are grateful she will continue to support ONE as a member of the Board. Mark’s global leadership, policy expertise and commitment to Africa will help us build on this strong foundation.”

Most recently, Green served as president of the Wilson Center in Washington, D.C. He brings extensive leadership experience across government, diplomacy, and international development, including serving as Administrator of the US Agency for International Development (USAID) and as a four-term member of the US Congress, where he helped shape major global health and development initiatives such as PEPFAR and the Millennium Challenge Corporation. He has also held senior roles at the McCain Institute, the Initiative for Global Development, and the US Global Leadership Coalition.

Green has a deep ties to Africa. He served as US Ambassador to Tanzania, taught in Kenya and spent time in South Africa as a child—experiences that have shaped his long-standing commitment to expanding opportunity and economic growth across the continent.

Bono, ONE’s co-founder, said, “Ndidi’s catalytic leadership has been a gift for ONE, ensuring the voices that ONE was founded to serve are paramount, and steering the organisation through unprecedented times in global health and global politics. Her guidance from Lagos through the ONE Board will be as important as ever.

“Her successor Ambassador Mark Green is an old friend of ONE’s core issues, a statesman with stellar credentials. He is of politics but above politics, respected by both republicans and democrats in Washington DC, with a global network built while running USAID and in the US foreign service. He is a great man to lead ONE in this moment when we need bodyguards for global health financing but also pragmatic visionaries who can work as partners in rethinking global health systems.

“Mark is a true believer in the American values that birthed PEPFAR, and in policies that foster partnership not patronage. And in the basic idea that where you live shouldn’t determine whether you live, which was and is the point of ONE.”

“I’m honored to join ONE at such an important moment,” said Green. “Africa’s future is central to global progress, and I’ve seen firsthand the ingenuity and potential across the continent. Starting on Africa Day is especially meaningful, and I look forward to working with partners, advocates, and leaders to accelerate progress, deepen partnerships, and deliver lasting impact.”

“ONE is entering its next chapter from a position of strength,” Nwuneli added. “We have a clear strategy, a strong leadership team, and a proven track record of results. In my role on the Board, I look forward to working with Mark to build on that foundation and take our impact even further.”

About The ONE Campaign:

ONE is a global, nonpartisan organization advocating for the investments needed to create economic opportunities and healthier lives in Africa. Since 2004, it has helped secure more than $1 trillion in new investments that build a safer, more prosperous world. ONE’s trusted advocacy combines hard-hitting data, grassroots activism and political engagement to influence decision-makers and drive lasting change. Learn more at one.org.