Royal jelly (RJ), a nutrient-rich secretion from the hypopharyngeal and mandibular glands of worker bees (Apis mellifera), has gained significant attention as a natural source of bioactive compounds with therapeutic potential. Among its various constituents, medium-chain fatty acids (MCFAs), notably 10-hydroxy-2-decenoic acid (10-HDA), 10-hydroxydecanoic acid (10-HDAA), and sebacic acid (SA), exhibit potent antioxidant, anti-inflammatory, immunomodulatory, and antimicrobial properties. In recent years, 10-HDA has emerged as the primary anticancer agent in RJ, demonstrating the ability to modulate key oncogenic pathways, including the induction of apoptosis, cell cycle arrest, and inhibition of angiogenesis and metastasis. This review provides a comprehensive analysis of the chemical composition, biosynthetic origin, and extraction techniques of RJ fatty acids (RJFAs), with a critical focus on their molecular mechanisms of anticancer action, including modulation of cell signaling pathways, DNA repair mechanisms, and immune response. We further explore their metabolic stability, bioavailability, and synergistic potential with conventional chemotherapeutics in models of lung cancer, breast cancer, liver cancer, and melanoma. Although promising, current limitations, including challenges in standardization, pharmacokinetics, and formulation, warrant further investigation. Future directions emphasize omics-driven approaches, such as genomics, proteomics, and metabolomics, as well as translational research to optimize the clinical applicability of RJFAs. Collectively, these insights position RJFAs, particularly 10-HDA, as compelling candidates for adjunctive cancer therapy and integrative oncology.