Former US Secretary of State Hillary Clinton was voted the 2013 winner of the Chatham House Prize by the think-tank on Wednesday for her work in promoting "a new era of US diplomatic engagement".
The London-based body said Clinton, who stood down this year after four years as the top US diplomat, was given the award "in recognition of her personal leadership in driving a new era of US diplomatic engagement and for her particular focus on promoting education and rights for women and girls".
Clinton, who is seen as the clear Democratic frontrunner for president, will be presented with the award at a ceremony in London later this year.
Previous winners include Myanmar democracy campaigner Aung San Suu Kyi and Brazil's former president Luiz Inacio Lula da Silva.
The prize is given annually to the statesperson deemed by members of the Royal Institute of International Affairs at Chatham House to have made the most significant contribution to the improvement of international relations in the previous year.
Congratulating Clinton on the award, Dr Robin Niblett, Director of Chatham House, said: "As Secretary of State she brought renewed energy to US diplomacy at a critical moment in international affairs, deepening key bilateral relations and strengthening US regional alliances.
"Her determination to reinforce the linkages between the goals of US diplomacy and development delivered significant achievements, especially in fostering new opportunities for girls and women across the world."