This Element aims to critically examine the philosophical thought of Im Yunjidang 任允摯堂 (1721–93), a female Korean Neo-Confucian philosopher from the Chosŏn 朝鮮 dynasty (1392–1910), and to present her as a feminist thinker. Unlike most Korean women of her time, Yunjidang had the exceptional opportunity to be introduced to a major philosophical debate among Korean Neo-Confucians, which was focused on two core questions-whether sages and commoners share the same heart-mind, and whether the natures of human beings and animals are identical. In the course of engaging in this debate, she was able to reformulate Neo-Confucian metaphysics and ethics of moral self-cultivation, culminating in her bold ideas of the moral equality between men and women and the possibility of female sagehood. By proposing a 'stage-approach' to feminism that is also sensitive to the cultural context, this Element shows that Yunjidang's philosophical thought could be best captured in terms of Confucian feminism.