Three-dimensional (3D) printing has become a transformative technology in pharmaceutical sciences, allowing the creation of customized drug delivery systems with precise control over shape, dosage, and release profiles. This review offers a thorough overview of 3D printing methods used in pharmaceuticals, including their materials, design strategies, characterization techniques, and current clinical and regulatory environments. Applications encompass personalized medicine, polypills, controlled-release implants, and new pediatric formulations. Despite its significant potential, 3D printing faces challenges related to scalability, quality control, and regulatory approval. Recent FDA approvals, notably of the first 3D-printed drug Spritam®, represent important milestones. Future advancements depend on unified guidelines, digital manufacturing integration, and AI-driven formulation improvements.