The convergence of additive manufacturing and biomaterials has opened unprecedented opportunities for precision medicine. 3D printing enables the fabrication of patient-specific implants, drug delivery inserts, and organ-on-chip models that closely mimic complex physiological environments. In oncology, 3D-printed biomaterials are reshaping the landscape of tumor modeling, localized therapeutic delivery, and personalized implants. In the field of neurology, hydrogel-based constructs, bio-printed scaffolds, and neural interfaces are offering innovative solutions for brain and spinal cord repair, neurodegeneration models, and drug screening platforms. This Special Issue aims to highlight the latest advances in material design, bio-ink development, computational modeling, and clinical translation of 3D-printed constructs tailored for cancer and neurological applications. We welcome original research, reviews, and short communications that explore innovative biomaterial strategies, translational potential and multidisciplinary collaborations.