As with other Pacific Island nations, the scientific efforts of the Kingdom of Tonga have been hampered through a lack of local scientists and science graduates. As observed globally, the region appears to face a steady decline in student interest and achievement in science, resulting in reduced uptake of science subjects in schools and universities. This study aims to provide insight into the attitudes of Tongan senior secondary students toward science, using the validated Test of Scientific Related Attitudes (TOSRA) instrument. The sample population comprised 2636 students of approximately 15–18 years of age, from 26 schools across Tonga. Overall, the mean attitudes of Tongan senior secondary students toward science were lower than that previously observed for Australian secondary students (Grades 7–10) and Fijian senior secondary students. A significant reduction in attitude was found between forms 5 and 6 for female students from rural areas, but not those from urban areas. No significant changes across different form levels were found for male students. The greatest difference between students’ perspectives was found for the normality of scientists, which may be indicative of cultural views toward this topic. Combined with the similar results of previous research in Fijian students, this may point toward broader differences in the attitudes toward science between students in Pacific Island countries more generally