Congenital long QT syndrome (LQTS) is a group of heritable conditions that are associated with cardiac repolarization abnormalities characterized by QT prolongation on electrocardiogram and the risk of life-threatening arrhythmias. The prenatal detection of LQTS presents significant challenges for clinicians, and a multidisciplinary approach is required for optimal prenatal and postnatal management. In this comprehensive literature review, we describe strategies for the fetal diagnosis of LQTS with variable initial presentation, genetic testing in suspected fetal LQTS, the utility of fetal magnetocardiography as an additional diagnostic tool, prenatal management, and postnatal treatment. We focus on a multidisciplinary team approach including fetal cardiology, adult and pediatric electrophysiology, neonatology, maternal–fetal medicine, and genetic counselors, all playing vital roles in the comprehensive prenatal management and orchestration of postnatal treatment to optimize neonatal outcomes.