This study examined teachers’ job satisfaction as a determinant of students’ learning outcomes in secondary schools in Osun State. A descriptive survey research design with a quantitative approach was adopted. A multistage sampling procedure was used to select 30 secondary schools, involving 60 teachers and academic performance data from 600 Senior Secondary School Two (SSS2) students. Teachers’ job satisfaction was measured using an adapted Teachers’ Job Satisfaction Questionnaire, which yielded a Cronbach’s alpha reliability coefficient of 0.86, while students’ learning outcomes in English Language and Mathematics were obtained through a pro-forma. Descriptive statistics and binary logistic regression were used to analyse the data at the 0.05 level of significance. The findings revealed that 66.7% of teachers reported a moderate level of job satisfaction, while 18.3% and 15.0% reported low and high levels, respectively. Approximately 44% of the observations reflected positive student learning outcomes, whereas 56% fell below the established benchmark. Binary logistic regression showed that teachers’ job satisfaction did not significantly predict students’ learning outcomes, Wald χ²(2) = 2.28, p = 0.32, with a Nagelkerke R² of 0.054. This study contributes context-specific empirical evidence from Osun State showing that teachers’ job satisfaction, when examined independently, has limited explanatory power for students’ learning outcomes, thereby reinforcing the need for a multidimensional approach to understanding student achievement. The study concludes that improving student achievement requires a broader approach that combines teacher welfare with instructional quality, school leadership, pedagogical competence, learning resources, and other school- and student-related factors.