Three-dimensional (3D) printing, as an advanced additive manufacturing strategy, exhibits remarkable translational potential in mammary reconstruction. Cumulative evidence confirms that 3D printing enables highly personalized mammary reconstruction, with markedly enhanced surgical precision and accelerated postoperative recovery. In autologous flap transplantation and breast-conserving surgery, this technology optimizes perioperative planning and surgical simulation, thereby improving therapeutic outcomes and lowering complication risks. Moreover, advances in 3D-printable biomaterials, including natural polymers, synthetic polymers, and decellularized adipose tissue matrix (DATM), open novel avenues for breast tissue engineering. Nonetheless, current limitations persist in biomaterial biocompatibility, mechanical matching, and faithful reconstruction of complex anatomical structures. This review summarizes the state-of-the-art progress and clinical applications of 3D printing in mammary reconstruction, highlights its technical merits, translational potential, and existing challenges, and provides a theoretical reference for additive biomanufacturing and tissue engineering strategies in post-oncological breast repair.