The study aims to determine a best fit model for organizational citizenship behavior as influenced by knowledge management, teaching performance, and faculty spirituality. A non-experimental quantitative research design employing descriptive, predictive and structural equation model to randomly selected 405 sectarian private school teachers in Davao Region. The collected data from an adapted survey questionnaire were analyzed using mean, pearson product moment correlation co-efficient, multiple linear regression and causal modeling. The study found out that the level of knowledge management, teaching performance, faculty spirituality and organizational citizenship behavior were described as very high which were always manifested among the sectarian private school teachers. Further, there is a strong significant correlation between knowledge management and organizational citizenship behavior teaching performance and organizational citizenship behavior and faculty spirituality and organizational citizenship behavior as the p values of all the measures is lower than the significant alpha value. In addition, the result shows a significant influence of the three exogenous variables namely knowledge management, teaching performance, and faculty spirituality towards the endogenous variable which is the organizational citizenship behavior. Furthermore, Model 3 satisfied the goodness of all criteria signifying the best fit model for organizational citizenship behavior. This implies that teachers with high level of conscientiousness and altruism of organizational citizenship behavior will contribute positively to the overall performance of the organization.The study aims to determine a best fit model for organizational citizenship behavior as influenced by knowledge management, teaching performance, and faculty spirituality. A non-experimental quantitative research design employing descriptive, predictive and structural equation model to randomly selected 405 sectarian private school teachers in Davao Region. The collected data from an adapted survey questionnaire were analyzed using mean, pearson product moment correlation co-efficient, multiple linear regression and causal modeling. The study found out that the level of knowledge management, teaching performance, faculty spirituality and organizational citizenship behavior were described as very high which were always manifested among the sectarian private school teachers. Further, there is a strong significant correlation between knowledge management and organizational citizenship behavior teaching performance and organizational citizenship behavior and faculty spirituality and organizational citizenship behavior as the p values of all the measures is lower than the significant alpha value. In addition, the result shows a significant influence of the three exogenous variables namely knowledge management, teaching performance, and faculty spirituality towards the endogenous variable which is the organizational citizenship behavior. Furthermore, Model 3 satisfied the goodness of all criteria signifying the best fit model for organizational citizenship behavior. This implies that teachers with high level of conscientiousness and altruism of organizational citizenship behavior will contribute positively to the overall performance of the organization.