The Appointment, Promotion, and Discipline (APD) Committee constitutes one of the most pivotal institutional mechanisms within Nigeria's public service architecture. Rooted in the colonial legacy of British administrative tradition and formally entrenched in successive Nigerian constitutional frameworks, the APD Committee serves as the operational arm through which the Federal Civil Service Commission (FCSC) and analogous state-level bodies exercise their constitutional mandates over civil servants. This paper examines the historical evolution, secretariat functions, and contemporary challenges confronting the APD Committee within the Nigerian civil service system. Drawing on a qualitative documentary review of relevant legal frameworks, including the 1999 Constitution of the Federal Republic of Nigeria (as amended), the Public Service Rules (PSR) 2008, and the Guidelines for Appointments, Promotions, and Discipline, the study critically interrogates the structural configurations, procedural operations, and administrative bottlenecks associated with APD Committees. The paper finds that while the APD Committee framework provides a systematic and legally grounded basis for managing human resources in the civil service, it confronts severe challenges, including political interference, nepotism, and inadequate secretariat capacity, delays in promotion exercises, inconsistent disciplinary procedures, and insufficient integration of technology into personnel management processes. The paper recommends comprehensive secretariat reform, merit-based reinforcement, digital transformation, and improved constitutional oversight as pathways to revitalising the APD system. The study concludes that the effectiveness of APD Committees is indispensable to governance quality and national development in Nigeria.