Leadership educators must consider how to most effectively develop youth knowledge, skills, attitudes, aspirations and leadership abilities when facilitating leadership development. During the first two millennia, leadership was adult-centered, with little focus on development. To develop effective leadership programs, it is essential that leadership educators: consider the implications of societal trends; project the contexts of 21st century leadership; understand and apply the principles of effective youth leadership development; and, develop meaningful adult and adolescent partnerships to prepare youth for success in the third millennium.