Math proficiency is considered a critical subject for entry into most science, technology, engineering, and math (STEM) occupations. This study examines the relationship between parental occupation and gender differences in students’ math performance, that is, the gender math gap. Using insights from theories of social and gender reproduction, we hypothesize that daughters of STEM-employed parents, and especially STEM-employed mothers, will score higher on standardized math tests than their peers with non-STEM parents. Multiple waves of panel data from the Early Childhood Longitudinal Study, Kindergarten Cohort (ECLS–K) featuring students in third, fifth, and eighth grades are used to examine these hypotheses. Results from random effects regression models confirm these hypotheses while also revealing support for STEM-employed father-to-son and father-to-daughter transmission of a math performance advantage. Also, regardless of parental occupation, a gender math gap remains evident. We conclude by discussing implications, study limitations, and directions for future research.