Formal education is subject to a confluence of factors that determine academic achievement of learners in primary schools based on teachers’ perceptions. The study was conducted using descriptive survey research design in Hamisi Sub-County in western Kenya. A sample of 110 teachers was obtained using simple random sampling strategy. The data was collected using questionnaires that were self-administered by the respondents. Chi-square test was used to determine the significance of the associations between the variables (p>0.05). Data was analysed using SPSS (version 25) software. The results showed that there were significant associations between teachers’ perception of learner’s family economic status (p>0.351) and family size (p>0.066) and their academic performance. No significant association existed between teacher perception of learners’ religious affiliation and their academic performance. Pearson’s correlation tests showed no linear correlation between the academic performance and religion, family economic status and family size (r<0.5). The study findings demonstrate that the way teachers’ perceive the social contexts of their learners may have a great bearing on their judgement of their learners’ academic performances, hence possible bias towards some of the learners based on the social perceptions they hold of the learners.