Self-control is normally taken to apply only to the domain of action: it seems to be only in connection with people’s actions and decisions that we attribute either self-control or its absence. Although it is not common parlance to speak of exercising self-control in the domain of belief, we argue in this paper that self-control is in fact a transversal phenomenon which applies both to action and to belief. Our discussion comes in three parts. In the first section, we offer a characterization of what it is to exercise self-control in its familiar context, action. Our proposal aims at capturing the phenomenon with greater generality than other suggestions from the literature have succeeded in doing. In the second section we argue that the conception of self-control which we proposed in the first section also applies to belief. While we grant that there will be some differences in how self-control is manifested in action and in belief, these differences do not undermine the basic takeaway: that agents can and do exercise self-control in both domains. Our rather speculative third section argues that our conceptual toolkit should also include a notion of self-control understood more diachronically and holistically, as a kind of character trait.