This chapter discusses personality and its relationship to sport performance. It defines personality as the unique characteristics that make a person who they are, which can be understood through examining psychological core, typical responses, and role-related behavior. Several approaches to studying personality are described, including trait, situational, interactional, and phenomenological approaches. Research findings show some relationship between personality and performance, though no definitive profile exists. Cognitive strategies, like mental preparation and coping with adversity, differentiate more successful from less successful athletes.