Abstract: Employee performance is a measure of the effectiveness of one’s job. It is also the way an individual does a job evaluated by its effectiveness. Hence, optimal job performance is often the primary outcome that organizations seek to attain. Therefore, this study examined the effect of leadership behaviour on the job performance of employees at Abu Dhabi National Oil Company, through the mediating role of involvement. In this quantitative research study, a structured questionnaire using a 5-point Likert scale was used to collect data from a total of 450 respondents from Abu Dhabi National Oil Company. The validity and reliability of the measurement and the structural models were ascertained.