Consistency in the self-concept across social contexts has been linked to various positive outcomes, including felt authenticity and well-being. Based on theories of social power (e.g., Keltner, Gruenfeld, & Anderson, 2003), we predicted that high-power individuals, disposed to greater control of their environments and freedom of self-expression, would exhibit greater self-concept consistency relative to their low-power counterparts. Across three studies, measured and manipulated high-power participants showed elevated self-concept consistency in terms of greater coherence and consistency in their spontaneous self-descriptions (Studies 1 and 2), and less variability in trait ratings of themselves across different contexts (Study 3), relative to low-power participants. Moreover, high-power participants' tendency to be more consistent in their self-concept explained their higher reports of authenticity relative to low-power participants (Study 3). Discussion focuses on the implications of these findings for health and well-being, and for power differences in other cultural contexts.