<p>The start of formal schooling occurs at a time in life when young children are undergoing rapid developmental changes, and the environments in which they grow, particularly the family, can have a lasting impact on their competence and learning outcomes. The current study examined variations in school readiness among preschool children and how these are associated with home and child characteristics. Specifically, this cross-sectional study considers the relations between (1) home characteristics, including socioeconomic status, migration background, home literacy, home numeracy, and home media environment; (2) child characteristics, such as age and gender; and (3) child outcomes, encompassing cognitive (i.e., intelligence and concentration), literacy, and numeracy skills, examined as key precursors of school readiness. The study sample consists of 500 children from Germany, with an average age of 77.6 months at school entry (<i>SD</i> = 4.3 months; age range = 60–89 months). Results indicate that socioeconomic status and enriched home learning environments, particularly the home numeracy environment, were positively associated with children’s cognitive, literacy, and numeracy skills. These factors also positively predicted timely school entry. In contrast, the home media environment and migration background were not significantly associated with timely school entry. By examining the interplay between these factors, the study aims to inform interventions and policies to ensure that all children, regardless of their background, are well prepared for successful educational transitions.</p>