School facilities play a crucial role in shaping the quality of education and students’ academic outcomes, yet many public secondary schools in Nigeria face infrastructural deficiencies that hinder effective teaching and learning. This study examines the impact of school facilities on students’ academic achievement in public secondary schools in the Federal Capital Territory, Abuja, Nigeria. The research adopted a descriptive survey design involving 500 respondents, including students, teachers, and school administrators, selected through stratified random sampling. Data were collected using structured questionnaires and observation checklists and analyzed using descriptive statistics, Pearson correlation, and regression analysis. The findings reveal that adequate school facilities—such as classrooms, laboratories, libraries, instructional materials, and sanitation infrastructure—significantly enhance students’ academic performance. Conversely, poor and inadequate facilities contribute to low student motivation, overcrowding, and reduced learning outcomes. The study further highlights that disparities in facility provision exist between urban and rural schools within the FCT. The findings underscore the need for increased government investment, effective maintenance culture, and equitable distribution of educational resources. The study concludes that improving school facilities is essential for enhancing students’ academic achievement and achieving quality education in Nigeria.