The underrepresentation of Black students in STEM (e.g., science, technology, engineering, and mathematics) remains a significant issue. Careers in STEM fields are some of the fastest-growing occupations (Carnevale et al., 2011) and fulfilling these positions has become a national concern. Previous work demonstrates that identity processes related to being a science student are the primary mechanism through which minority students choose a science occupation (Stets et al., 2017) and science identity is widely accepted as the greatest predictor of success in STEM (Chang, 2020; Lockhart et al., 2022). However, students' science identity development often occurs in institutions and STEM departments where students face racial microaggressions (Lee et al., 2020; Miles et al., 2020). Racial microaggressions (RMAs)— subtle racialized offenses– are frequent experiences that Black students encounter (Anderson et al., 2020; Burt et al., 2016). While previous work details the negative effects of RMAs, few studies have explored how RMAs affect science identity development. This study intends to bridge this gap by incorporating students' racialized experiences into our understanding of science identity. Drawing on Identity Theory (Burke, 1991; Stets & Burke, 2014), the current study quantitatively explores how RMAs affect students' science identity and other key factors related to success in STEM (i.e., science self-efficacy and sense of belonging). Black undergraduate STEM majors at a minority-serving institution in the southeastern part of the United States were invited to complete an online survey. Findings revealed significant associations between RMAs, science identity, and STEM career intentions. While a moderation analysis did not indicate that RMAs moderated the relationship between science identity and students' STEM career intentions, a mediation analysis revealed a significant indirect effect of RMAs on STEM career intentions through science identity. A multiple linear regression analysis also revealed that sense of belonging, science self-efficacy, and STEM career intentions significantly predicted science identity. The three-predictor model accounted for 47% of the variance in science identity. These findings suggest that RMAs and science identity interact to shape students’ STEM persistence highlighting the importance of fostering inclusive and supportive Findings revealed significant associations between RMAs, science identity, and STEM career intentions. While a moderation analysis did not indicate that RMAs moderated the relationship between science identity and students' STEM career intentions, a mediation analysis revealed a significant indirect effect of RMAs on STEM career intentions through science identity. A multiple linear regression analysis also revealed that sense of belonging, science self-efficacy, and STEM career intentions significantly predicted science identity. The three-predictor model accounted for 47% of the variance in science identity. These findings suggest that RMAs and science identity interact to shape students’ STEM persistence highlighting the importance of fostering inclusive and supportive