Research has shown the importance of routines for optimal child development. A systematic review can offer a detailed overview of the evidence linking routines to child outcomes, particularly in high-risk settings. This review aimed to elucidate the association between daily routines and child development and to pinpoint the protective role of routines in high-risk environments. A search of PubMed and PsycINFO databases yielded literature from 1950 to June 2020. Out of 4297 initial hits, 170 studies met the selection criteria. Findings mainly indicate that routines are associated with positive developmental outcomes in children, covering cognitive, self-regulation, social–emotional, academic skills, and overall mental and physical health. The results also underline the protective power of routines in challenging environments. The study suggests possible mechanisms through which routines influence child outcomes and recommends avenues for future research, supporting evidence-based strategies to encourage parental use of routines.