Tyrannicide has traditionally been distinguished from political assassination in terms of the difference between public and private life. Tyrannicide was a self-sacrificing act for public benefit (and so morally esteemed); common assassination, its opposite, namely, a self-serving act for private gain (and correspondingly censured). Terrorist assassinations, though similarly condemned, raise a special problem since they purport to be self-denying acts for the public good. It is argued that a satisfactory distinction between them and tyrannicide cannot be drawn on the basis of historical or behavioral criteria alone, and consequently a supplementary “teleological” criterion is required. This leads to a consideration of the “classical” and “ideological” styles of politics as the respective contexts of tyrannicide and terrorism. In context, terrorism and tyrannicide can be seen as not only categorically different but also antithetical kinds of political violence. Terrorism, in short, is a form of tyranny of which tyrannicide is a negation.