Preventive genomics may very well be the most advanced emerging field in pediatric medicine to date. Considered to be in its infancy at about 20 years old, the use of genomic medicine became a reality with the completion of the Human Genome Project in 2001. It is a new, developing field and with the potential to predict a child’s future health so profound it must be understood as the way to prevent future suffering for children. The birth of a phenotypically healthy baby belies their genetic undercurrent, which may contain mutations manifesting as devastating disorders. Historically, standardized newborn screening has been done on all infants at birth, with the goal of detecting and diagnosing disorders as early as possible. Commonly screened disorders include phenylketonuria, sickle cell disease and cystic fibrosis among other endocrine and metabolic disorders. This screening protocol only focuses on selected disorders and therefore has become limited in scope for early diagnoses of many serious genetic diseases. Traditionally, genome sequencing is only performed after a child has presented with symptoms of a disorder. Preventive genomics has changed this narrative to preemptively detect disorders before any symptom is present and before any indication of illness is found. The medical uses of genomic sequencing in children are myriad but we also found that the ethics of presymptomatic detection of adult-onset disorders has faced controversy. In question are ethical implications of testing when children are not capable of consent, and the long-term effects it may have on them with the awareness of what their medical future holds. In this review, we examine the history of the field of genomic medicine and its potential to change the course of disease, leading to better outcomes in pediatric patients. In particular, we explore how genomics can be used to advance the diagnosis of genetic disorders and decrease the time to diagnosis in utero, infancy, and childhood. We also probe the role of genomic sequencing and its capability to identify disorders far earlier than ever before, allowing for the possibility of gene therapy and cures for those children who are affected.