Employees with optimistic and affirmative feelings and having enthusiasm towards achieving the business objectives are key to sustain and continue in this competitive business world. Hence, leader of an organization is substantial in reaching the highest in the competitive world, as the role of a leader plays a main role in inspiring and guiding the actions of employees. The purpose of this study is to examine how transformational leadership of a leader and psychological empowerment of subordinates are related to OCB demonstrated by employees, where it identified as the voluntary commitment of the employees apart from well-defined duties and responsibilities. 130 employees of apparel sector manufacturing organizations in Sri Lanka were selected as respondents to respond about their boss's leadership, their individual empowerment, and whether they go further from their basic requirements of the job. Self-administered anonymous questionnaire used to collect data, which consist of standard measures. Transformational leadership was significantly positively related with OCB of employees and psychological empowerment act as a partial mediator on the relationship between transformational leadership and OCB of employees. This paper contributes on knowledge areas of transformational leadership and psychological empowerment on OCB while support in creating practices to develop psychological empowerment of employees and direct leaders to emphasis on improving OCB through changing their style of leadership.