The study investigated the relationship between principals’ ethical leadership practices and teachers’ job effectiveness in public secondary schools in Enugu State. The study was guided by two research questions and two hypotheses were tested at 0.05 level of significance. A correlational research design was adopted for the study. The population of the study comprised 15,321 teachers in the 296 public secondary schools in Enugu State. The sample size for this study consisted of 1,072 teachers drawn using a proportionate stratified sampling technique. Two sets of instruments titled “Principals’ Ethical Leadership Practices Questionnaire (PELPQ)”, and ‘‘Teachers’ Job Effectiveness Scale (TJES)’’ were used for data collection. The face validated was determined by three experts, two from the Department of Educational Management and Policy, and one from the Department of Educational Foundations in the Measurement and Evaluation Unit, Faculty of Education, Nnamdi Azikiwe University. Cronbach's alpha method was used for a test of internal consistency of the instruments, which yielded overall coefficients of 0.78 for PELPQ and 0.81 for TJES. The researchers and three research assistants collected data for the study and a 97% return was achieved. Pearson Product Moment Correlation Coefficient was used to answer the research questions and test hypotheses. The findings of the study revealed, among others, that there was a strong and significant relationship between principals’ ethical power-sharing practices and teachers’ job effectiveness in public secondary schools in Enugu State. Further result indicated that there was a strong and significant relationship between principals’ people-orientation practices and teachers’ job effectiveness in public secondary schools in Enugu State. Based on the findings, it was recommended among others that Enugu State Secondary Education Management Board should conduct regular and continuous seminars for principals to refresh and update their knowledge on engaging in ethical power-sharing practices for improving teachers’ job effectiveness.