Motivation derived from a sense of truly valuing or enjoying one’s pursuits (“wanting to do it”)—as opposed to motivation born of external demands or other people’s expectations (“having to do it”)—is associated with goal-pursuit success and overall well-being. But what determines the quality of motivation in the first place? Many theoretical perspectives identify features of the task or situation as determinants, but have largely ignored the potential contribution of individual self-regulatory tendencies. We ask here whether individual differences in self-control may be associated with an individual’s likelihood of “wanting to” pursue current goals, operationalized as the momentary experience of autonomous motivation. We first describe an exploratory experience-sampling study that documented the association (Study 1) and prompted subsequent development of the hypothesis that trait self-control and autonomous motivation are related. A second experience sampling study replicated the effect (Study 1R) and 2 cross-sectional studies helped hone its interpretation (Studies 2 and 3). We then employed an experimental paradigm to test whether the association between trait self-control and autonomous motivation is goal-dependent. Consistent with an instrumental, self-regulatory account of the association, we found that trait self-control was related to autonomous motivation for a novel task only when an individual expected to continue working on that task (Study 4). Employing an integrative perspective, this work expands our understanding of trait self-control by identifying it as a candidate contributor to motivation quality, and, more generally, helps to integrate otherwise disparate approaches to understanding motivation.