Purpose: This study aimed to identify parental factors associated with smartphone overuse in preschoolers. Methods: A systematic review was conducted according to PRISMA guidelines. Relevant studies published in peer-reviewed journals from 2009 to June 2019 were identified through systematic search in 10 electronic databases (PubMed, CINAHL, Cochrane Central, EMBASE, Web of Science, NDSL, KISS, KMbase, KoreaMed, and RISS). Standardized effect sizes were calculated to quantify the associations of parental factors with smartphone overuse in preschoolers using meta-analysis. Results: A total of 30 cross-sectional studies involving 7,943 participants met the inclusion criteria. The following were negatively correlated with smartphone overuse in preschoolers: mother’s parenting self-efficacy (r =-.35), mother-child attachment (r =-.28), mother’s positive parenting behavior (r =-.28), mother’s positive parenting attitude (r =-.25), and father’s parenting involvement (r =-.15). Further, maternal factors such as smartphone addiction tendency (r =.41), parenting stress (r =.40), negative parenting behavior (r =.35), negative parenting attitude (r =.14), smartphone usage time (r =.26), employment status (r =.18), and age (r =.12) were positively correlated with smartphone overuse in preschoolers. Conclusion: Several parental factors influence smartphone overuse in preschoolers. These findings emphasize the need to assess and enhance the parental factors identified in this study to prevent smartphone overuse in preschoolers. Accordingly, we recommend the development of preventive interventions to strengthen parent-related protective factors and mitigate risk factors.