This study examines the relationships between school processes and literacy in public schools that serve low-income families in a midsize city in Colombia. We focus on four categories of school processes: instructional practice; school-community engagement; well-being of students, teachers, and parents; and community belonging. We present two key results. First, we find considerable variation in literacy performance across schools, despite serving students with similar family background characteristics. Second, we find community belonging to be the most salient school process for predicting literacy. Among measures of community belonging, higher levels of students' sense of belonging and lower levels of bullying were associated with higher literacy. This study contributes to the field of international and comparative education by highlighting the importance of relational and interpersonal dimensions of school processes for children's learning. Our study also demonstrates the value of adopting an interdisciplinary lens that combines economics, child development, and sociology to better understand the links between school processes and student learning.