This empirical article addresses a gap in the literature by testing Transparency as a mediator in the relationship between Transformational Leadership (TL) and Employee Performance (EP) among Administrative and Diplomatic Officers in Malaysian Public Sector. A survey of 380 Management and Professional Group (grade 41-54) of ADO produced 208 completed questionnaires, which were used to collect the data for this study. The sample size for this investigation was calculated using the G*power software. The data in the study was analysed using the structural equation model (SEM), specifically the partial least squares-based structural equation modelling. The measurement and structural models were each subjected to two stages of analysis. The findings show that transparency has a substantial impact on EP. It has supplied sufficient evidence to support the idea that employees who are transparent perform better. The transparency consistently mediates the link between TL and EP. The study is projected to make three contributions: it will add to the literature database on the causes of transparency, it will change our understanding of the relationship between TL and EP by introducing transparency as a mediator, and it will serve as a basis for future researchers.