Critical theory has usually been regarded as a unique amalgamation of ideas drawn from Marx, Weber, and Freud, among other sources. What this view tends to minimize or overlook is the unique role of the critical theorists, beginning with Georg Lukács (a critical theorist "before the fact"), in reviving, interpreting, and further developing a distinctively Hegelian approach to the problems of knowledge, culture, and politics. This chapter first demonstrates the role of critical theorists in reviving Hegelianism in the early twentieth century. Then, it outlines the role of Hegelian philosophy as the basis for concepts of totality in the thought of Georg Lukács and Max Horkheimer, and of rationality in the thought of Herbert Marcuse and Theodor Adorno. The critique of, and then return to, Hegel in the work of Jürgen Habermas and Axel Honneth is also considered. The chapter concludes with an evaluation of three historical interpretations of the significance of the Hegelian element in critical theory, a consideration of the limits of Hegelianism for critical theory, and a suggestion of a fourth interpretation.