Among the variety of approaches, competencies—knowledge, skills, abilities, and personal attributes, that are critical for being an effective, successful performer in a given job— are being as a basis of many human resource development systems and sub-systems such as Competency-Based Training (CBT) which are recognized to have more effective and long-lasting results and sustainable performances for the job and organization. This article presents a competency model for Communications Regulatory Authority (CRA) of the I. R. of Iran. Iran's CRA regulates Information Communications and Telecommunications sector in Iran to ensure sustainability, competitiveness and transparency among the service providers, customers and shareholders; thus, there is no doubt that the experience and expertise of CRA's personnel is exclusively important, and developing its human capital is among the most critical strategies of this organization. To this end, the CRA's competency model is developed based on mixed methods research includes literature reviews, benchmarking studies, 13 semi structured interviews and questionnaires filled by 47 experts, the process of which is summarized in this paper. The model consisted of forty competency groups, classified in four tiers, namely fundamental, managerial, organizational, and professional competencies, which are elaborated in this article.