William Ayers, American academic and activist
William Charles Ayers (; born December 26, 1944) is an American elementary education theorist. During the 1960s, Ayers was a leader of the Weather Underground militant group, described by the FBI as a terrorist group. He is known for his 1960s radical activism and his later work in education reform, curriculum and instruction.

In 1969, Ayers co-founded the Weather Underground, a self-described communist revolutionary group that sought to overthrow American imperialism. The Weather Underground conducted a campaign of bombing public buildings (including police stations, the United States Capitol, and the Pentagon) during the 1960s and 1970s in response to U.S. involvement in the Vietnam War. The bombings, which caused no fatalities, resulted in Ayers being hunted as a fugitive for several years, until charges were dropped due to illegal actions by the FBI agents pursuing him and others.

Ayers 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 U.S. presidential campaign, a controversy arose over his contacts with then-candidate Barack Obama. He is married to lawyer and Clinical Law Professor Bernardine Dohrn, who was also a leader in the Weather Underground.