Over the past five decades, scholars of intercultural communication have attempted to define, describe, and otherwise operationalize the concept of competency in an intercultural interaction. This study constructed a comprehensive theory of intercultural communication competence (ICC) grounded in the extant literature and the practical or everyday understanding of the concept. Using classroom data that was validated by a metasynthesis of existing qualitative or ethnographic studies describing ICC, the academic definitions and lay descriptions were each explored and then compared to find points of convergence and points of divergence. The comparative analysis provided the foundation for the development of tenets: ICC is an outcome; ICC is externally perceived and measured; and ICC is bound by the cultural context in which it takes place, conditions regarding interaction goals and power roles of the interactants, and culture specific elements for the holistic ICC theory proposed by this study. An examination of the implications of the newly constructed ICC theory and its future application and implications were explored.