This study explored the perceived relationship between school heads competencies, leadership practices, and the sustainability of school communities in standalone senior high schools in the Division of Laguna. In particular, it assessed the extent of school heads competencies, leadership practices, and the level of schools sustainability. It also measured the significant difference in the perception of teachers concerning school heads competencies, leadership practices, and schools sustainability. The significant relationships between these variables were also tested. Additionally, it identified which specific competencies and leadership practices, singly or in combination, significantly predict sustainable school communities. This study used a descriptive-correlational design to examine the relationship between school heads competencies, leadership practices, and the sustainability of school communities. The respondents included one hundred ninety-two (192) teachers from fourteen (14) standalone senior high schools in Laguna, chosen via purposive sampling. Data were collected using self-made questionnaires. Based on the presented and interpreted data, the respondents rated school heads competencies, leadership practices, and the sustainability of school communities as very high. There were notable differences in teachers perceptions of these aspects. Significant relationships were found between school heads competencies and sustainability, as well as between leadership practices and sustainability. Additionally, some independent variables significantly predict the sustainability of school communities. In conclusion, this research found significant differences in perceived school heads competencies, leadership practices, and school sustainability. It also revealed a significant relationship between these factors and the sustainability of school communities, leading to the rejection of all hypotheses. These correlations underscore the importance of effective leadership and management in fostering sustainable school environments. Additionally, some independent variables significantly predict sustainability, further highlighting the critical role of school heads competencies and leadership practices. Based on the studys conclusions, several recommendations were made. School heads may articulate a clear vision for sustainability, encompassing environmental, social, and economic aspects, to inspire stakeholders. Schools may also establish clear metrics and benchmarks, regularly monitor progress, and celebrate achievements to ensure the effectiveness of sustainability initiatives and maintain motivation.