Heiresses have been overlooked in seventeenth and eighteenth-century theatre criticism. When they are discussed, it is usually alongside the prodigal hero’s resolution of his financial difficulties and rakish behavior through marriage. Financially and sexually desirable, the heiress is therefore an important and influential character in the marriage plot. This article presents a literary historical analysis of the changing representation and function of the heiress in comedy, to argue that the evolvement of the heiress in the marriage plot reveals emergent and shifting discourses about money, family and sentiment in the long-eighteenth century. The treatment of the heiress on the eighteenth-century stage reflects a sentimental response to the role of money in marriage in line with the ideology of companionate marriage. Whereas, on the late seventeenth-century stage, the heiress acts as economic manager and wittily protects her financial interest.