In this study, we interviewed Olympic athletes about their perceptions of their leaders and managers, with a particular focus on perceptions of negatively-valenced and socially undesirable characteristics and their effects. The results highlight five main dark characteristics: self-focused, haughty self-belief, inauthentic, manipulative, and success obsessed. The findings also indicate negative effects of such characteristics (viz. performance and career threats, affected confidence, pressure and anxiety, and a lack of support) and positive effects of such characteristics (viz. motivation, resilience and coping skills, opportunities, and learning and awareness). Hence, it appears that not only are leaders and managers’ personalities “different shades of grey” (Arnold & Fletcher, 2012, p. 26) but also the effects they have are too. The findings are discussed in relation to previous pertinent research, and with regard to their implications for policy development and future research.