School readiness at kindergarten is an important predictor of children's future academic success (Duncan et al., 2007). While early pre-academic and behavioral skills are important for all students, there is considerable inequality in students' levels of readiness at the start of school (Coley, 2002; Lee & Burkam, 2002; Razza, Martin & Brooks-Gunn, 2010; Ryan, Fauth, & Brooks-Gunn, 2006; Welsh, Nix, Blair, Bierman & Nelson, 2010), and research has pointed to a range of out-of-school and poverty-related factors that contribute to these inequalities (Coley, 2002; Dearing, 2008; Foster, 2002; Hill, 2001; Razza et al., 2010; Ryan et al., 2006). This study utilizes relational developmental systems theory (Lerner, 2006; 2011) to examine the individual and contextual factors that co-act dynamically to shape and predict student outcomes. Specifically, this study extends the body of research on early child development by examining the factors that predict school readiness skills within a sample of 521 young children preparing to enter the first grade from urban early education programs. Multilevel regression models indicate that student characteristics, classroom characteristics, and peer contexts each predict students' school readiness scores, and that the interactions among these variables make unique contributions to the prediction of school readiness scores as well. Implications for theory, policy, and practice are discussed along with recommendations for future research.