As complex systems, organizations face the challenge of continuing efficient operations and adapting to a changing environment. This challenge is often framed in the context of strategic leadership: leaders are seen as managing the tension between long- and short-term objectives and between exploration and exploitation. This article looks at how leadership and the actions of leaders relate to these adaptive tensions and how the effectiveness of leadership can be measured in a complexity science context. To do this, leadership is conceptualized as an organizational meta-capability that processes information about the environment and the organization, and then changes the organization by reconfiguring and building new capabilities. The article suggests a family of possible metrics, discusses the complexity of their interactions, and suggests future research to further the field's understanding of the important question: how individual human actions influence the social systems in which they occur.