Adepoju Ismaila AROWOLO2024-05-162024-05-162022-12Kate TurabianPhDhttps://repository.lcu.edu.ng/handle/123456789/118Employee performance in public sector which transformed into organisations performance deemed to have nosedived in government agencies in Nigeria including agency used for this study. Employee behaviour in government organisations is also deemed to be of no enthusiasm especially in the area of job performance, commitment and satisfaction, all these are characterized by stagnation, corruption, nepotism and quick money-making syndrome and ineffective reward system. This study examined the mediating effect of performance evaluation, leadership role on behavioural outcome in the agency and was anchored on contingency theory and theory of expectation. A descriptive method was adopted, the population of the study was 275 same with the sample size. Questionnaire was distributed to 275 respondents and the response rate is 88.36 percent and significance level for all analyses was 5%. The data was analyzed and the results showed on the strength of the specific indirect impact (β= 0.243, t= 2.295; p= 0.022) and Q2 value (0.273, 0.243), and concluded that leadership role significantly mediate the interaction between performance evaluation and employee behavioural outcomes in the agency. It is recommended that the government agency should be more innovative and adopt the Key Performance Indicators that is strategic, functional and custom-made to their operations. It crucial that the agency should consistently focusing on contingency leadership style that triggers high level of motivation and inspire the entire employee of the organization. Similarly, comparative studies on constraint of performance evaluation reports and employee behavioural outcomes in other government agencies should be considered in future studies. Future studies may also consider the longitudinal survey design to explain interaction between performance evaluation, leadership role and employee behavioural outcome in Nigeria. Factors like good government policies, regulations and amendment of relevant laws on compensation and pension are resilience and strategic factors for future studies. Keywords: Performance Evaluation, Leadership Role, Behavioural Outcome, Management by Objective, 360 Degree Feedback, Turnover Intention, Job Commitment, Job Satisfaction Words counts: 297enThesis