Heidt, William A., 1961-

William A. "Bill" Heidt (born 1961) is an American diplomat who was the United States Ambassador to Cambodia from 2015 to 2018. He was nominated on April 7, 2015, by President Barack Obama to succeed William E. Todd. He was confirmed by the U.S. Senate on August 5, 2015, and sworn in on September 14, 2015. As ambassador, Heidt launched initiatives to expand trade and investment between the U.S. and Cambodia, strengthen respect for human rights and democracy, build Cambodia’s nascent technology sector, and empower Cambodia’s women entrepreneurs. His term ended on November 28, 2018. Thereafter, he served on the faculty of the Eisenhower School for National Security and Resource Strategy at National Defense University from January to November 2019, teaching classes on economics, industry analysis and American Studies. He was named Deputy Commandant and International Affairs Advisor at the Eisenhower School on November 4, 2019.

Born in Erie, Pennsylvania, he attended Penn State University, earning his B.A. in 1984, and George Washington University, where he graduated with an M.A. in 1986. He joined the Foreign Service in 1988, with his first posting in Poznan, Poland, as a consular officer. Heidt returned to Washington in 1990 to serve as an economic officer in the Office of Bilateral Trade Affairs. In 1992, he moved to a similar role in the Office of Korean Affairs and ultimately was an economic officer in the Bureau of Economic and Business Affairs.

Heidt's first assignment in Southeast Asia came in 1997 when he was posted for two years to the embassy in Phnom Penh, Cambodia as an economic and commercial officer. He was recognized for his efforts to improve workers’ rights, especially those of apparel workers and to counter illegal logging. In 2000, he was sent to Jakarta, Indonesia, as a finance and development officer. He returned stateside in 2003 to be a special assistant in the Office of the Under Secretary for Economics, Business and Agricultural Affairs. Heidt returned to Jakarta the following year as economic officer in the embassy there.

Heidt was posted to the United Nations in New York in 2007 as a counselor for economic and social affairs. He returned to Poland in 2009 to serve as deputy chief of mission in the Warsaw embassy. From 2012 until commencing his ambassadorship, Heidt served as executive assistant to the Under Secretary for Economic Growth, Energy and Environment.

Heidt and his wife, Sotie, a contract specialist with the Federal Bureau of Investigation, have a son, Allen.