Problem statement: In social open systems, there are basically two determinant of organizational behavior: "organizational" and "personal." The former is mostly related to the aim of the organization, the necessities of the work, whereas the latter is concerned with the traits of the employee. Various studies have focused on the traits of the employee along with their different dimensions. One of these is the locus of control, which can be measured and evaluated as a dimension of personal trait. Although there are some studies that were carried out with students, teachers, and principals regarding locus of control, so far no research has been done with educational supervisors who are crucial actors in the current educational process. Purpose of Study: The purpose of this study is to determine the locus of control of educational supervisors. Methods: The research consisted of 340 educational supervisors working in 18 cities, which are located in the fourth and fifth educational service regions of Turkey. The data collection tool consists of two parts. The first is "General Information Form," which aims to collect personal information concerning educational supervisors. The second part is the 29-item Rotter's Internal-External Locus of Control Scale (I-E-LOC Scale), which aims to determine the locus of control of educational supervisors. In data analysis, techniques such as Kolmogorov Smirnov test, independent sample t-test, one way ANOVA, and Scheffe test were used. Findings and Results: According to the results, there was no significant effect of variables such as field, faculty, education level, teaching tenure, and incentives (p>0.05) on locus of control of the participants. However, supervisory tenure did have a significant effect on locus of control (p<0.05). Conclusions and Recommendations: It was determined that educational supervisors had a tendency to internal locus of control (M = 9.09). Having an internal locus of control for an educational supervisor may contribute to the task performance, which is determined by legal regulations and ethical principles of the profession. In addition, it can create and environment that reinforces the tendency of having internal locus of control for the target population. To enable supervisors to have more internal locus of control, mainly two things can be suggested. First, applicants for supervisory positions should be chosen among already internal locus of control teachers and/or administrators. To realize this, some practices must be abolished. These practices are about the perceptions of unjust processes in which proficiency is not a criterion to be selected and appointed, and which can be manipulated and predictable. Second, another perception of supervisors may be changed. It is the perception that they play a role that is heavily dependent on external supervision during their task performances, in terms of authority they have. This perception can be positively changed during pre-service or in-service periods.