Leadership is both a research area, and a practical skill encompassing the ability of an individual, group or organization to "lead", influence or guide other individuals, teams, or entire organizations. Often viewed as a contested term, specialist literature debates various viewpoints, contrasting Eastern and Western approaches to leadership, and also (within the West) North American versus European approaches.

U.S. academic environments define leadership as "a process of social influence in which a person can enlist the aid and support of others in the accomplishment of a common and ethical task". Basically, leadership can be defined as an influential power relationship in which the leader's power promotes movement/change in their followers. Others have challenged the more traditional managerial view of leadership which believes that it is something possessed or owned by one individual due to their role or authority, and instead advocate the complex nature of leadership which is found at all levels of the institution, both within formal roles.

Studies of leadership have produced theories involving traits, situational interaction, function, behavior, power, vision and values, charisma, and intelligence, among others.