Low levels of education are a powerful predictor of anti-immigration sentiment. However, there is little consensus on the interpretation of this correlation: is it causal or is it an artifact of selection bias? We address this question by exploiting six major compulsory schooling reforms in five Western European countries-Denmark, France, Great Britain, the Netherlands, and Sweden-that have recently experienced politically influential anti-immigration movements. On average, we find that compelling students to remain in secondary school for at least an additional year decreases anti-immigration attitudes later in life. Instrumental variable estimates demonstrate that, among such compliers, an additional year of secondary schooling substantially reduces the probability of opposing immigration, believing that immigration erodes a country's quality of life, and feeling close to far-right anti-immigration parties. These results suggest that rising post-war educational attainment has mitigated the rise of anti-immigration movements. We discuss the mechanisms and implications for future research examining anti-immigration sentiment.