Abstract: There is limited research on the relationship between science, technology, engineering, and mathematics (STEM) occupational history and cognitive function in later life, especially among military veterans, who may be at greater risk for later-life cognitive decline. This study examines a nationally representative sample of military veterans to address this gap in knowledge. We obtained data for this cross-sectional study from the 2011–2014 waves of the National Health and Nutrition Examination Survey on veterans (n = 464) and civilians (n = 2093). Cognitive function was assessed using three tests: the immediate and delayed memory word recall test, the animal fluency test, and the digit symbol substitution test. The primary independent variable is STEM occupational history, operationalized through the question: “Thinking of all the paid jobs or businesses you ever had, what kind of work were you doing the longest?”. Although our study was limited by the cross-sectional study design (i.e., we could not make causal inferences about cognitive decline), results suggest that cognitive function may be better in veterans who have had a STEM occupation than those who have not. Future studies should explore veteran cognitive function by rurality, as previous reports have shown that rural-dwelling veterans are less likely to be involved in a STEM career.