Gender is one of the most salient social identities, particularly during early adolescence. However, factors related to adolescents' gender attitudes remain underexamined. We examined links between adolescents' gender discrimination, felt-gender similarity, and intergroup gender attitudes. Participants were 270 adolescents in the United States (Mage = 12.95 years, SD = 1.33; 47.4% adolescent girls; 63.7% White, 12.2% Latinx, 10.7% Black, 4.1% Asian, 5.6% multiracial, and 3% indigenous). Path analyses showed that gender discrimination negatively predicted adolescents' attitudes towards own- and other-gender peers. Felt own-gender similarity positively predicted own-gender attitudes as expected, but other-gender similarity did not predict other-gender attitudes. Further, own- and other-gender similarity did not interact to predict adolescents' gender attitudes. However, adolescents' attitudes towards other-gender peers were more negatively impacted by gender discrimination for those who felt highly similar to own-gender peers than for those with average or low own-gender similarity. Findings inform potential strategies to improve adolescents' gender attitudes.