There is important empirical evidence that shows that quality of leadership at a school level is one of the factors with the greatest impact on students' performance. The purpose of this article is to provide territorialized diagnosis of quality of school leadership in Spain and its regions based on PISA 2015 Spanish sample. Several quantitative indicators of leadership are defined for this purpose. The relationship between school leadership and economic, social, and cultural status (ESCS), because of its interest in defining new educational compensation policies has been analyzed. In addition, leadership indicators by type of school (public, charter, and private school) to compare the predominant leadership models in each of them, have been considered. Our main results reveal: (a) low percentages for principals who apply key forms of school leadership with sufficient frequency; (b) the weakness of public versus private schools, whether sustained by public funds or not, in leadership practices with the greatest impact; (c) significant differences between regions for all the leadership indicators considered; (d) an association between leadership and academic performance whose strength is close to 20%. From these empirical results, different recommendations are made in the field of educational policies and practices.