This study aimed to investigate the impact of teacher absenteeism on students' academic performance in lower secondary schools in Nyenga Sub-County, Buikwe District, Uganda. The research sought to measure the level of teacher absenteeism, identify its causes, and propose solutions to mitigate the problem. A mixed-methods approach was employed, with quantitative data collected through structured questionnaires administered to teachers, school administrators, and students. Qualitative data were gathered through interviews with key stakeholders in the education sector. The quantitative data were analyzed using multiple logistic regression analysis in SPSS and STATA to examine the relationships between absenteeism and various factors such as teacher age, experience, school type, health, job satisfaction, family responsibilities, and work environment. The regression results indicated that teacher absenteeism was significantly influenced by health issues (OR = 1.78, p < 0.05), job dissatisfaction (OR = 1.62, p < 0.05), and family responsibilities (OR = 1.54, p < 0.05). The analysis also revealed that teachers working in rural schools and those with fewer years of experience were more likely to exhibit higher absenteeism rates. The study concluded that teacher absenteeism in Nyenga Sub-County is primarily driven by health problems, family obligations, and job dissatisfaction. It was also found that improving teacher welfare, providing health insurance, enhancing school working conditions, and offering professional development opportunities were effective solutions to reduce absenteeism. Based on the findings, the study recommends that the government and school management implement comprehensive health insurance policies, foster positive work environments, offer flexible work arrangements for teachers with family responsibilities, and prioritize regular training and career advancement opportunities. Additionally, it is recommended that school administrators and local governments collaborate to create policies that address the underlying causes of absenteeism and promote teacher retention.