The purpose of this study was to investigate the associations between school-based racial discrimination by teachers and peers and academic outcomes (i.e., classroom misconduct, absenteeism, academic performance, school readiness, and school behavioral problems) over one year (Time 2) through the moderation of perceived social support from friends. Participants were 599 Latinx adolescents (56% girls; M[subscript age] = 14.51, SD = 0.55) from middle schools located in the suburbs of a large Midwestern United States city. They completed questionnaires on their perceived school-based racial discrimination and social support from friends. Their teachers completed questionnaires on classroom misconduct and school readiness, measured twice over one year. School records of academic performance, absenteeism, and school behavioral problems were also collected twice over one year. The findings indicated that social support from friends was negatively associated with Time 2 classroom misconduct, absenteeism, and school behavioral problem, but positively associated with Time 2 school readiness and academic performance. School-based racial discrimination by teachers and peers were both related positively to Time 2 classroom misconduct, absenteeism, and school behavioral problems, whereas both types of discrimination were related negatively to Time 2 school readiness and academic performance. Social support from friends buffered against academic outcomes associated with discrimination by teachers. Similar patterns were found for discrimination by peers, but only for Time 2 academic performance and absenteeism. These results suggest that high perceived social support from friends positively impacts Latinx adolescents' academic outcomes after experiencing school-based racial discrimination while low levels increase such negative outcomes.