(1) Background/objectives: This study aims to systematically review and conduct a meta-analysis of factors influencing fertility intentions among South Koreans. This research is crucial given South Korea's lowest-in-the-world fertility rate of 0.72 in 2023, necessitating rapid and effective policies to address this demographic challenge; (2) Methods: Articles published from database inception through April 2024 were collected from five Korean databases using keywords based on the PEO (Population, Exposure, Outcome) framework. Following PRISMA guidelines, 35 articles were selected. The effect sizes and network of predictors related to fertility intention were analyzed using the R statistical package; (3) Results: A meta-analysis of the effect sizes of factors influencing fertility intentions revealed that the husband's involvement in parenting (ESr = 0.131), women's education level (ESr = 0.127), socioeconomic status (ESr = 0.116), and the expected gender of the child (ESr = 0.068) showed statistically significant positive effects. Conversely, women's age (ESr = -0.175), parental stress (ESr = -0.146), and household labor ratio (ESr = -0.117) showed statistically significant negative effects. The network analysis further elucidated the complex interrelationships among these factors; (4) Conclusions: This study suggests the need for multifaceted policy approaches to address Korea's low fertility, emphasizing promoting men's participation in parenting, supporting women's education and career development, reducing parenting stress, supporting work-family balance, and ensuring economic stability. These findings provide important insights for policymakers and researchers addressing the complex issue of low fertility in South Korea and may inform more effective interventions to boost fertility rates.