Project Managers’ (PMs) competencies are critical issues for international development projects (IDPs), and the success of IDPs is largely dependent on how prudently and effectively a PM manages the IDPs operations. So far, the topic of PMs Competencies is mainly explored in the private sector context using a survey-based research approach, and very few attempts have been made to examine the competencies of PMs in the IDPs sector. Accordingly, this study examines the PMs’ competencies at each phase of the project life cycle (Initiation, Planning, Execution, Monitoring and Controlling, and Closing) by drawing on the sample of 15 PMs from the IDPs’ sector by employing a Delphi method, which enables aggregation of experts’ opinions in a more structured and systematic manner. Findings of this study proposed five of the most critical competencies within each phase of the project life cycle and ranked based on their relative importance, for example, leadership, communication, planning, innovation, motivation, etc. The findings contribute to emerging literature and bring new insights on project managers’ competencies in the IDPs sector.