["Journal of Research on Adolescence, Volume 36, Issue 2, June 2026. ", "\nAbstract\nDevelopmental changes in daily ethnic–racial discrimination and its influence on mental health among ethnic–racial minority young adults remain understudied. Using two waves (30 days at each wave) of daily diary data from 165 Asian university students in Canada (67% women; Mage = 18.11 years, SD = 0.94 at Wave 1), this study investigated changes in the daily associations between ethnic–racial discrimination and internalizing problems, as well as the moderating role of daily peer support (cultural socialization, preparation for bias, and general social support), during the first and third years of university. Multilevel structural equation modeling showed that, at the within‐person level, daily ethnic–racial discrimination was significantly associated with increased internalizing problems on the same day at Wave 1 (B = 1.35, 95% CI [0.99, 1.71]) but not at Wave 2 (B = 0.57, 95% CI [−0.05, 1.19]). Daily peer cultural socialization (B = −0.84, 95% CI [−1.65, −0.03]) and preparation for bias (B = −1.21, 95% CI [−2.09, −0.27]) buffered the association between discrimination and internalizing problems at Wave 1; however, these patterns were not observed at Wave 2. These findings underscore the first year of university as a vulnerable period when daily exposure to ethnic–racial discrimination can compromise mental health among ethnic–racial minority students. Peer cultural socialization and preparation for bias can serve as effective buffers during this time. Higher education institutions should prioritize interventions that foster culturally sensitive peer support systems that help create an inclusive and affirming environment for first‐year ethnic–racial minority students.\n"]