This study sought to establish the influence of principal‟s leadership styles on teachers‟ professional commitment in Kericho Sub-county, Kenya. Specifically the study endeavored to establish the influence of Principals‟ Democratic Leadership style on Teachers‟ Professional Commitment in public secondary schools in Kericho Sub-county. This research was informed by the situational leadership theory and descriptive research design was adopted to guide the study. The sub-county has 31 public secondary schools. In the 31 schools there are a total of 31 principals, 155 Heads of Departments and 400 Teachers. All the 31 principals were selected to participate in the study because the sub county has recorded a decline in KCSE performance in the last two years. Five (5) HODS‟ in charge of academics from each school were purposively selected because of their special complementary roles in the leadership and management of schools. Simple random sampling was used to select five subject teachers in each school, one from each academic department to participate in the study; also 3 sub county quality assurance and standards officers‟ were selected. Therefore a total of 344 respondents comprising of 31 principals, 155 HOD‟s, 155 subject teachers and 3 SCQASOs constituted the total sample size. Data was collected using questionnaires which were administered to principals, HODs and subject teachers while interview schedules were used to guide discussions with the SCQASOs. Validity of the instrument was determined by the supervisors, lecturers in the department of Education Kisii University. For reliability, a test re-test of the findings was calculated and a Pearson‟s correlation coefficient of 0.856 was obtained. Data was analyzed using descriptive statistics with aid of Statistical Packages for Social Sciences (SPSS) computer program while the results from interviews were analyzed qualitatively and thematically. Results revealed that democratic leadership style was the dominant style employed by principals in Kericho Sub-County together with the democratic practices employed point to a leadership that recognizes ideals of democracy in management. Other practices, principals delegate tasks and assignments to staff members (M=1.94, SD = 0.923); Principals ensure that members of staff feel involved and relevant in decision making process (M = 2.10, SD = 1.075); The study recommended that there is need to consider blending the leadership styles since each has some contribution to make indirectly to learner performance. The researcher paid keen attention to research ethical issues and got the informed consent of the respondents and guarded against plagiarism and ensured confidentiality.