Identity politics has become a widely used term, commonly to describe the activities of socio-political movements the purpose of which is to achieve social justice. Such widespread use has often been at the expense of a more thorough analysis of its efficacy as a conceptual tool, and of whether the political actions to which it refers are adequate for that purpose. This article, an introduction to a collection of essays focused on that question, critically considers various ways that identity politics may be (and has been) characterised and whether those characterisations are sufficient to permit a single clear definition of the concept. It also overviews arguments about the extent to which, and in what respects, putting identity politics to work can succeed in achieving social justice.