In parallel with the socioeconomic transformations, there have been transformations in the management styles of the institutions in the historical process. Since the Industrial Revolution, management has been accepted as a branch of science all over the world, especially in Europe and America. Management and manager are essential concepts for social life and business world. However, in parallel with the change in the concept of management, the concept of manager also undergoes a change and the meaning attributed to the concept of manager and expectations differ. The acronym for the word 'Chief Executive Officer', the CEO is, in the simplest terms, the highest level officer of a company. The CEO, who is of vital importance for the company in terms of their position and responsibilities, has a wide range of authority and responsibility. Like all concepts and phenomena, the concept of CEO also changes and transforms over time. So much so that in today's intensely competitive business environment, the CEO is accepted as a value in brand status and is increasing its sphere of influence day by day. In this context, in terms of the business world, the concept and position of the CEO, the functions and responsibilities associated with the CEO, the knowledge, skills and competencies represented by the CEO is a subject that is talked about and discussed. This study focuses on the concept of CEO and considers the functions and responsibilities of the CEO from a conceptual perspective. Within the scope of the study, the concept of CEO, the managerial-organizational meaning and importance of the CEO, their duties and responsibilities, the knowledge, skills and competencies they should have are discussed. The aim of the study is to make a descriptive contribution to the literature by clarifying the duties and responsibilities of the concept of CEO.