Timothy Endicott Wirth is an American politician from Colorado who served as a Democrat in both the United States Senate (1987–1993) and the United States House of Representatives (1975–1987). He also served in several appointed roles in government, including as Deputy Assistant Secretary for Education during the Nixon Administration and Under Secretary of State for Global Affairs for the U.S. State Department during the Clinton Administration. From 1998 to 2013, he served as the president of the United Nations Foundation, and currently sits on the Foundation's board.

The United Nations Foundation is a charitable organization headquartered in Washington, DC, that supports the United Nations and its activities. It was established in 1998 with a $1 billion gift to the United Nations by philanthropist Ted Turner, who believed the UN was crucial for addressing the world's problems. Originally primarily a grantmaker, the UN Foundation has evolved into a strategic partner to the UN, mobilizing support to advance the Sustainable Development Goals (SDGs), and help the UN address issues such as climate change, global health, gender equality, human rights, data and technology, peace, and humanitarian responses. The UN Foundation's main work occurs through building public-private partnerships, communities, initiatives, campaigns, and alliances to broaden support for the UN and solve global problems. The UN Foundation has helped build awareness and advocate for action on, among others, antimicrobial resistance, regional action on climate change, local implementation of the SDGs, as well as global campaigns such as Nothing But Nets against malaria, the Measles & Rubella Initiative, the Clean Cooking Alliance, Girl Up, Shot@Life, and the Digital Impact Alliance, among others. In March 2020, the UN Foundation was also a key founder of the COVID-19 Solidarity Response Fund on behalf of the World Health Organization (WHO), helping to raise over $200 million USD within the first six weeks to support the global response to the COVID-19 pandemic.