In general, the study was conducted to determine the effects of leadership styles and conflict management strategies on the school performance of school principals of public secondary high schools in Region III. A total of 77 respondents participated in this study. The survey questionnaire was utilized in gathering the data needed. Data were analyzed using descriptive statistics. The age of the respondents ranged from 38 to 64 with a mean of 51.30 years old and a standard deviation of 6.46 years. Findings revealed that the majority of the school principals were female, married, Ph.D. degree holders who had less than 13 years of experience as a school principal, had been serving their school for five years or less, were holding Principal IV positions, were receiving a monthly salary of Php 65,319.00 – Php 73,157.00 (55.84 %) and had passed the National Qualifying Examination for School Heads (NQESH). With regard to school performance, results showed that the majority (72.73%) of the school principals had an outstanding OPCRF rating, Performance-Based Bonus scores higher than 90 %, and under lower average National Assessment Test (NAT) rating. The socio-demographic characteristics of the respondents were significantly related to the performance of school principals in terms of OPCRF rating, PBB Score, and NAT results. Transformational leadership styles such as idealized behavior (IB), inspirational motivation (IM), idealized attributes (IA), and individualized consideration (IC) were correlated to the school performance in terms of OPCRF rating, PBB score, and NAT results while conflict management strategies such as obliging, avoiding, integrating, dominating and compromising were correlated also to the school performance in terms of OPCRF rating, PBB score, and NAT results. Idealized attributes were found influential predictors of NAT performance while dominating strategy was found to be an influential predictor of OPCRF performance
