Abstract Associations between education and oral health have frequently been reported, but until now there has been no causal evidence. Exploiting exogenous variation in the duration of schooling due to 1947 and 1972 reforms in mandatory schooling in the United Kingdom, we examined the causal relationship between education and tooth loss in older age. We conducted a cross-sectional study using data from waves 3 (2006–2007), 5 (2010–2011), and 7 (2014–2015) of the English Longitudinal Study of Ageing. We used a 2-stage least squares instrumental variable approach and included 5,667 respondents (average age = 67.8 years; 44.4% were men) in the analyses, of whom 819 (14.5%) had no teeth. The schooling reforms increased the duration of education by an average of 0.624 years (95% confidence interval: 0.412, 0.835). For respondents born within ±6 years of the pivotal cohorts, a 1-year increment of education causally reduced the probability of edentulism by 9.1 (95% confidence interval: 1.5, 16.8) percentage points. The effects were stronger for the 1947 reform than for the 1972 reform. Results were robust to broadening of the cohort bandwidth and functional form of the cohort trend. The findings suggest that investment in education produces improved oral health later in life.