Low levels of education are a powerful predictor of anti-immigrationsentiment. However, there is little consensus on the interpretationof this correlation: is it causal or is it an artifact of selectionbias? We address this question by exploiting six major compulsoryschooling reforms in five Western European countries—Denmark,France, Great Britain, the Netherlands, and Sweden—that haverecently experienced politically influential anti-immigrationmovements. On average, we find that compelling students to remain insecondary school for at least an additional year decreasesanti-immigration attitudes later in life. Instrumental variableestimates demonstrate that, among such compliers, an additional yearof secondary schooling substantially reduces the probability ofopposing immigration, believing that immigration erodes a country’squality of life, and feeling close to far-right anti-immigrationparties. These results suggest that rising post-war educationalattainment has mitigated the rise of anti-immigration movements. Wediscuss the mechanisms and implications for future researchexamining anti-immigration sentiment.