Sexual education has become an essential component of comprehensive health education programs worldwide. However, views and understanding about sexual education can differ greatly among people and have a big impact on how people’s mental health. The researcher in this study used a diagnostic research design. All the higher secondary school students in the Theni District, Tamil Nadu constituted the study population. The researcher used stratified random sampling in this study, and the sample size was 500 higher secondary students in the Theni District, Tamil Nadu. A semi-structured interview schedule was developed to better understand the socio-demographic conditions of the students and to measure their attitudes, knowledge, and perceptions relating to sexual education. The mental health of the respondents was measured by the Rand Mental Health Inventory (MHI) with 18 items. There is a significant positive link between knowledge of sexual education and attitudes toward it and mental health. This study found that the more people knew about sexual education, the more positive their attitudes were toward it. A better level of understanding regarding sexual education promotes mental wellness. Knowledge of sexual education correlates negatively with age. It demonstrates that younger respondents had a higher level of knowledge regarding sexual education than older respondents. There is a significant link between perception toward sexual education and attitudes toward sexual education. According to this study, individuals who are younger have more positive opinions toward sexual education than those who are older. There is no significant correlation between attitude toward sexual education and mental health. Perception of sexual education has a significant positive link with mental health. The study found that the respondents had a positive attitude toward sexual education and are in good mental health. Age had no significant link with perceptions of sexual education. This study will provide important implications for health education programs and methodologies by highlighting the necessity of addressing attitudes toward sexual education in promoting favorable mental health outcomes.