Human beings, each considered as a single actor within society
- Activists - Individuals who take direct action to achieve a social or political end
- Adams, Charles - Attorney, tax historian and author
- Adams, John - Second President of the United States
- Adams, Samuel - American revolutionary leader, organizer of the Boston Tea Party
- Aristotle - Greek philosopher, tutor of young Alexander the Great
- Armentano, Dominick T. - Economics professor (emeritus) at the University of Hartford
- Authors - Fiction and non-fiction writers of books, stories and other literature
- Authors, Science Fiction - Writers of fictional accounts with scientific or pseudo-scientific bases
- Ayau, Manuel - Founder of the Universidad Francisco Marroquín, Guatemala