This study investigates the predictive roles of agreeableness, conscientiousness, and neuroticism on ethical leadership and examines the moderating effect of ethical role modelling in these relationships. Data were obtained from 205 public service leaders in Malaysia through a disproportionate stratified sampling method. Analyses were performed using SPSS (Version 23) and Partial Least Squares Structural Equation Modelling (Version 4). Results indicate that agreeableness and conscientiousness are significantly and positively associated with ethical leadership, whereas neuroticism demonstrates a significant negative association with ethical leadership. Importantly, ethical role modelling emerged as a significant negative moderator in the relationships between conscientiousness, neuroticism, and ethical leadership. These findings enrich the ethical leadership literature by underscoring the influence of personality traits in the public sector and extending Social Learning Theory through evidence of the moderating role of ethical role modelling. The study offers a nuanced perspective on the interplay between individual traits and social context in shaping ethical leadership behaviour. From a practical standpoint, the results provide actionable insights for public sector organizations, emphasizing the value of targeted recruitment, leadership development initiatives, and ethics-focused mentoring programs. Such integrated strategies can cultivate a culture of integrity and accountability, ultimately reinforcing public trust in governance.