Little is known about student teacher attitudes towards pupils with autism spectrum disorder (ASD). We explored the predictors and mediators of attitudes toward ASD across three groups of European student teachers (N=704), within three national settings (Sweden N=262, Finland N=251, England N=191). Key findings suggest greater contact quality, perceptions of positive social norms towards ASD, and perceptions of competence of people with ASD individually predict more positive attitudes, whereas greater affective intergroup anxiety predicts more negative attitudes. Contact quantity or perceptions of course knowledge, were not associated with attitudes. Implications for teacher training in the three national settings are discussed.