In this chapter we have reviewed the most influential leadership theories. Trait approaches identify the characteristics required to be perceived as a leader and to be successful in the role. Intelligence, extraversion, conscientiousness, openness to experience, and integrity seem to be leadership traits. Behavioral approaches identify the types of behaviors leaders demonstrate. Both trait and behavioral approaches suffered from a failure to pay attention to the context in which leadership occurs, which led to the development of contingency approaches. Recently, ethics became an explicit focus of leadership theories such as servant leadership and authentic leadership. It seems that being conscious of one’s style and making sure that leaders demonstrate the behaviors that address employee, organizational, and stakeholder needs are important and require flexibility on the part of leaders.