Anthusa of Mantinea was an 8th-century Byzantine anchoress and abbess who lived near Constantinople. After practicing asceticism in mountain solitude, she established two monasteries, one for men and one for women. As the leader of the female community, she oversaw ninety nuns noted for their spiritual discipline. Because she resisted the iconoclastic policies of Emperor Constantine V, she faced arrest and torture alongside her followers and her nephew, the abbot of the male monastery.