It's commonplace to assume that an agent who is ignorant or harboring false beliefs within a particular domain is thereby less, or even non-autonomous in that domain. It is for this reason that informed consent is considered indispensable in respecting patients' autonomy, and that paternalism is considered no block to preventing people from acting on the basis of at least some false beliefs, as in J.S.Mill's famous bridge example. What is far less common, however, is to find any sustained attention given to the question of how, and to what extent, ignorance and false beliefs affect autonomy. In this paper I make a start at filling that gap. I will first sketch a new theory of autonomy, which I will argue is necessary to fully capture the variety of ways in which ignorance and false beliefs affect autonomy. I will then work through a range of examples to show precisely how, and to what extent, ignorance and false beliefs affect an agent's autonomy. I will conclude by gesturing towards the ways in which this analysis sheds new light on the possibilities for soft paternalism.