The purpose of this study was to validate the authentic leadership questionnaire(ALQ) comprising 4 factors of 16 items initially developed by Avolio, Gardner and Walumbwa(2007) to see if it is applicable to the schools in Korea. The data for this research was collected by survey from 236 school teachers of elementary, middle and high schools across the nation. The results of the exploratory factor analysis(EFA) and confirmatory factor analysis(CFA) confirmed three sub-scales, 15 items comprising relational transparency, internalized moral perspective and self-awareness. The results of the model test produced a good fit to the data. The analysis of the second-order factor model revealed that 3-factors were well converged into the higher factor of the authentic leadership. The estimated internal consistency alphas(Cronbach’s alpha) for three factors were at acceptable levels. The results of this study demonstrated that the three-factor model, 15 items of authentic leadership questionnaire was a valid tool for measuring authentic leadership in schools of Korea, and suggested that further research be conducted to develop the items more appropriate to the schools in Korea.