Three-dimensional (3D) printing, also termed additive manufacturing, has emerged as a transformative technology in pharmaceutical sciences, enabling the fabrication of complex drug delivery systems with unprecedented precision and customization. Conventional manufacturing processes are constrained by fixed dose strengths and standard geometries, limiting their capacity to address inter-patient pharmacokinetic variability. The present review aims to comprehensively examine the major 3D printing technologies applied in pharmaceutical formulations, including fused deposition modeling (FDM), inkjet printing, binder jetting, stereolithography (SLA), and selective laser sintering (SLS), evaluating their utility in designing personalized dosage forms and controlled-release systems. Key applications discussed encompass patient-specific oral dosage forms, polypill systems incorporating multiple active pharmaceutical ingredients (APIs), pediatric and geriatric formulations, and drug-eluting implants. The approval of Spritam (levetiracetam) by the U.S. Food and Drug Administration (FDA) in 2015 established a pivotal regulatory precedent that has accelerated translational research in this domain. Mechanisms of drug release from 3D printed matrices, including diffusion-controlled, erosion-mediated, and geometry-dependent release modulation, are critically evaluated. Despite remarkable advances, significant challenges remain in material biocompatibility, printing scalability, regulatory harmonization, and clinical validation. Future perspectives emphasize the integration of artificial intelligence in print parameter optimization, the development of pharmaceutical-grade printable biomaterials, and point-of-care manufacturing platforms. In conclusion, 3D printing holds immense potential to redefine pharmaceutical manufacturing toward individualized, patient-centric drug therapy.