Prenatal exposure to fever and infections has been linked to various neurodevelopmental disorders, but it is not yet known whether more subtle effects on neurodevelopment may exist as well. Therefore, we aimed to investigate whether these early-life exposures were associated with academic performance in childhood and early adolescence. Children and mothers who were enrolled in the Danish National Birth Cohort during 1996–2002 were included in this study. Information on fever and infections common in pregnancy was prospectively collected in 2 pregnancy interviews and linked with assessments of academic performance from the 2010–2013 Danish National Tests. Hierarchical multilevel linear regression of 216,350 assessments made in 71,850 children born to 67,528 mothers revealed no differences in academic performance among the children according to prenatal exposure to fever (odds ratio (OR) = 1.01, 95% confidence interval (CI): 1.00, 1.03), any infection (OR = 1.00, 95% CI: 0.99, 1.01), genitourinary infection (OR = 1.01, 95% CI: 0.99, 1.02), prolonged cough (OR = 1.00, 95% CI: 0.99, 1.02), or diarrhea (OR = 0.99, 95% CI: 0.97, 1.00). The findings were supported in different types of academic assessments, with different timings of exposure, and in sibling comparisons. This large population-based study suggested that prenatal exposure to fever and common infections does not affect the child's basic school performance.