Recently arriving to US schools, 405 immigrant adolescents in a large, urban high school shared backgrounds and perspectives on what variables and sociocultural factors contributed to their sense of belonging in their new school. This study occurred in 2019-2020 and examined belonging during a xenophobic socio-political climate. This study examines what predictors and experiences, if any, contributed to belonging for a large population of multilingual, newcomer youth. This research extends the body of literature to include a large, linguistically and culturally diverse, adolescent newcomer population to test hypotheses that gender, GPA, grade level, employment status, relationships, and family factors impact belonging. In this descriptive, single-site case study of newcomers enrolled in an International Academy (IA), semi-structured online interviews (N = 14) and a survey (N = 391) were utilized. Anchored with Goodenow's belonging definition and scale, quantitative data analysis included regression analysis to reveal three demographic belonging predictors. Qualitative data analysis leveraged emergent coding of newcomer comments to surface five belonging contributing factors. Results indicated that females had higher sense of belonging scores, while students of smaller language groups and students paying rent had statistically significantly lower scores. Additionally, five sociocultural school factors emerged that contributed to belonging: support networks, language, participation opportunities, safety, and recognition. Conclusions resulted for improving secondary school structures, practices, and climate to cultivate belonging for newcomers. Directly from students, this study presents educators with opportunities to ensure newcomers feel included, accepted, and valued through peer support networks, post-secondary preparation, and linguistic, emotional, and physical safety.