This study is about the phenomenon of leadership. Existing studies of leadership have failed to address the complex, multidisciplinary, processual, and collective nature of leadership. Attempts to appear scientific have focused on the forms of leadership rather than its universal processes. Following an analysis of existing theories of leadership viewed from disciplinary frames, the purpose of this study is to propose a new theory of leadership constructed within a cultural frame. The nature of leadership can be understood best when it is defined as a cultural expression containing complex sets of interdependent variables. Insofar as the study presents a cultural theory of leadership, it is informed by anthropology and includes ethnographies as case studies on leadership, including the works of Barth, Leach, Bailey, and Kracke. Inasmuch as the case studies serve to instantiate the proposed theory and the study is founded on the possibility of comparison, integration, and generalization, the research methodology utilized is that of grounded theory as outlined by Glaser and Strauss (1967). The critical properties of both culture and leadership are identified, revealing an isomorphic congruence between the properties of both categories. A comparative analysis between the properties of culture and leadership reveals the coterminous relationship between the two, suggesting leadership is a cultural expression. Among the conclusions drawn are the following: (a) the nature of leadership is linked to the nature of culture; (b) leadership is essentially a cultural expression; (c) the universal dimension of leadership can only be defined in terms of process; and (d) leadership can only be studied as a multidisciplinary phenomenon