<p>Most people disagree with racism, yet very few stand up to actively address or confront it. This is problematic because such <i>antiracism</i> is essential to overturn structures of racial injustice. Relative to research promoting positive intergroup attitudes, little is known about the antecedents of antiracism. We use recent advances in the asserted (i.e., proactive) versus assisted (i.e., affiliative) nature of autonomy to identify the motivational predictors of both positive attitudes and antiracist actions. In study 1 (<i>n</i> = 431), we found that assisted autonomy was a stronger predictor of warm outgroup feelings (e.g., allophilia, admiration), and that this effect was mediated by empathy. Conversely, only asserted autonomy linked to confrontation of racism and willingness to take action on behalf of racialized groups. In study 2 (<i>n</i> = 290), we assessed antiracist intentions before and after presentation of an antiracist message. Asserted (but not assisted) autonomy predicted an increase in antiracism after message exposure. Results suggest that asserted versus assisted autonomy striving have divergent links to outgroup feelings and behavior. We highlight the separate motivational pathways toward two important but functionally distinct outgroup outcomes and discuss how human autonomy can mobilize antiracist efforts.</p>