This paper shows that Hannah Arendt was a theorist both of secularization as a process and the secular as a goal of modern politics. It reconstructs these arguments in her corpus, especially her book "On Revolution," and argues that this dimension of her work may have been a response to Carl Schmitt (and is in any event now usefully read in such a way). The paper ends by examining how Arendt might reply to currently influential challengers of a secular politics.