This Element offers a systematic outline of ancient conceptions and uses of suspension of belief (understood broadly) while engaging with contemporary philosophy. It discusses the notion of epochē ('suspension of judgement') and other related terms, like aporia, aphasia, paradox, hypothesis, agnosticism, and Socratic wisdom. It examines the Academic and Pyrrhonian sceptics and some of their arguments and strategies for suspension. It also includes the use and conditions for suspension of belief in other philosophers like Socrates, Plato, Aristotle, the Stoics, Plotinus, Protagoras, and Democritus. The Element is divided into four thematic sections, each addressing one of the following questions: What is suspension of belief? When does it arise? What could its scope be? And what are its practical and moral implications?