The study examines the influence of cultural diversity on core HR functions within Nigeria public sector Findings reveal a significant positive direct effect of Cultural Diversity on Recruitment and Selection (Estimate = 0.837, p < 0.001), Training and Development (Estimate = 0.783, p < 0.001), and Performance Evaluation (Estimate = 0.925, p < 0.001). Inclusive leadership policies influenced by cultural diversity positively impact Performance Evaluation (Estimate = 0.095, p = 0.029). Embracing diversity and implementing inclusive practices enhances HR processes, fosters training, ensures fair evaluations, and cultivates inclusive leadership. The study underscores diversity and inclusion's strategic importance for organizational success, supported by theories from social psychology, organizational behavior, and HR management. It suggests that by embracing diversity, organizations can foster cross-cultural understanding and develop effective solutions to implementation challenges, contributing to organizational effectiveness and success in the Nigerian public service.