Several recent studies devote themselves to Mary Astell's feminist theory of virtue—her ‘serious proposal to the ladies’ to help women obtain wisdom, equality, and happiness, despite the prejudices of seventeenth-century custom. But there has been little scholarship on Astell's conception of heroic virtues, those exceptional character traits that raise their bearers above the ordinary course of nature. Astell's appropriation of heroic virtue poses a number of philosophical difficulties for her feminist ethics—heroic virtues are characteristically masculine, exceptional, and individualistic, ill-suited to a community-oriented feminism aimed at ordinary women. In this paper, we seek to investigate—and then dispel—these key difficulties. Our intention is to generate a new understanding of Astell's theory of virtue as a unique and sophisticated theory that equalizes and naturalizes heroic virtue for women.