William Charles „Bill” Ayers (born December 26, 1944) is an American elementary education theorist and a former leader in the counterculture movement who opposed US involvement in the Vietnam War. He is known for his 1960s radical activism and his current work in education reform, curriculum and instruction. He is a retired professor in the College of Education at the University of Illinois at Chicago, formerly holding the titles of Distinguished Professor of Education and Senior University Scholar. During the 2008 US Presidential campaign, a controversy arose over his contacts with candidate Barack Obama. He is married to Bernardine Dohrn, who was also a leader in the Weather Underground.