Gestational diabetes mellitus (GDM) is a prevalent condition with significant health implications for mothers and infants. Numerous guidelines exist for managing GDM, reflecting the diversity of healthcare systems, regional practices, and research advancements. This narrative review compares and contrasts eight prominent guidelines: American Diabetes Association (ADA), International Association of Diabetes and Pregnancy Study Groups (IADPSG), National Institute for Health and Care Excellence (NICE), American College of Obstetricians and Gynecologists (ACOG), Endocrine Society, Royal College of Obstetricians and Gynecologists (RCOG), Canadian Diabetes Association (CDA), and European Association for the Study of Diabetes (EASD). Common themes include emphasizing lifestyle modifications, particularly medical nutrition therapy, and physical activity, as the cornerstone of management. When lifestyle changes are insufficient, insulin is frequently recommended as first-line pharmacotherapy, although variations in diagnostic criteria and glycemic targets exist. Metformin use is also suggested by some guidelines. This review underscores the complexity of GDM management, highlighting the need for individualized care to achieve optimal maternal and fetal health outcomes.