The self-regulation literature commonly is said to lack theoretical order. This paper explores the possibility that advances in personality science may foster clarity in this literature. Our goals are two-fold. We remind readers of conceptual distinctions that are central to contemporary personality science, that are necessary to the attainment of theoretical order in the self-regulation literature, yet that sometimes are overlooked. Secondly, we suggest that basic and applied students of self-regulation would profit by capitalising on recent advances in personality science that explore intra-individual personality structure and dynamics. We review theory and research on the architecture of intra-individual personality systems and applications of this work to three domains: health, clinical, and work/industrial/organisation psychology.