<p>Three-dimensional (3D) printing offers precise control over dosage form geometry, internal structure, and drug distribution, enabling the fabrication of advanced drug delivery systems beyond the capabilities of conventional manufacturing. The increasing recognition of circadian regulation in disease and drug response has underscored the need for chronotherapeutic approaches that align drug release with biological rhythms. This review examines pharmaceutical 3D-printing technologies, including extrusion-based, inkjet, light-based, and powder-based methods, with a specific focus on their application in programmable, multilayered drug delivery systems for personalized and chronotherapeutic therapy. This work integrates manufacturing principles, chronobiological considerations, and data-driven design strategies to provide a unified framework for time-programmed, patient-specific drug delivery. Structural design strategies enabling delayed, pulsatile, and multi-phase release are discussed. Artificial intelligence is presented as an enabling framework that supports data-driven design, formulation screening, and process optimization for personalized and chronotherapeutic dosage forms. Key challenges related to material selection, process reproducibility, quality assurance, and regulatory translation are highlighted, and priority research directions for clinical advancement are identified.</p> Graphical Abstract <p></p>