This paper aims to provide a systematic review of the literature on school effectiveness, with a focus on identifying the main factors that contribute to successful educational outcomes. The research question that this paper aims to address is: What are the main factors of school effectiveness? The research was interested in several descriptors such as school, effectiveness/efficiency theories, effectiveness/efficiency research, and factors. Studies were reviewed through two databases: JSTOR and ERIC (published within the 2016-2022 period). The paper defines several categories that are exposed within school effectiveness research. Within these categories, various factors that affect the students’ outcomes and the defined effectiveness at school are listed. As the results show, the issue of school effectiveness is a multifaced challenge as the effectiveness of schools is a complex concept that can be measured through various indicators such as academic achievement, student engagement and teacher satisfaction. The review of school effectiveness has revealed that several factors contribute to effective schools, such as strong leadership, effective teaching practices, a positive school culture and parental involvement. Additionally, school resources, such as funding and facilities, can impact school effectiveness, particularly in under-resourced communities.