And if by chance I wake at night and I ask you who I am, oh take me to the slaughterhouse I will wait there with the lamb. —Leonard CohenWhatever satisfies the soul is truth. —Walt WhitmanI prefer to be true to myself, even at the hazard of incurring the ridicule of others, rather than to be false, and to incur my own abhorrence. —Frederick DouglassIn this chapter, we present research and theory pertaining to our multicomponent perspective on authentic functioning. We begin with a historical account of various philosophical perspectives on authentic functioning and briefly review several past and contemporary psychological perspectives on authenticity. We then define and discuss our multicomponent conceptualization of authenticity and describe each of its components and their relationships to other constructs in the psychology literature. Next, we present an individual differences measure we have developed to assess dispositional authenticity and each of its components, and we report findings attesting to the adequacy of its psychometric properties. In addition, we present findings from a variety of studies we have conducted to examine how authenticity relates to diverse aspects of healthy psychological and interpersonal functioning. These studies pertain to a wide range of phenomena, including the following: verbal defensiveness, mindfulness, coping styles, self‐concept structure, social‐role functioning, goal pursuits, general well‐being, romantic relationships, parenting styles, and self‐esteem. Following this, we discuss potential downsides or costs for authentic functioning and describe some future directions for research on authenticity.