Sexual objectification is a common theme in contemporary feminist theory. It has been associated with the work of the anti-pornography feminists Catharine MacKinnon and Andrea Dworkin, and, more recently, with the work of Martha Nussbaum. Interestingly, these feminists' views on objectification have their foundations in the philosophy of Immanuel Kant. Fully comprehending contemporary discussions of sexuality and objectification, therefore, requires a close and careful analysis of Kant's own theory of objectification. In this paper, I provide such an analysis. I explain what is involved, for Kant, in the process of objectification, what it really means for a person to be an object (what Kant calls an ‘object of appetite’), and finally deal with his reasons for thinking that marriage can provide the solution to the problem of sexual objectification. I then proceed to some contemporary feminist discussions on sexual objectification, showing how influential Kant's ideas have been for contemporary feminist thinkers MacKinnon, Dworkin, and Nussbaum. My analysis of these feminists' work focuses on the striking similarities, as well as the important differences, that exist between their views and Kant's views on what objectification is, how it is caused, and how it can be eliminated.