“Smart materials” refers to materials that respond to stimuli in the environment, in consequence altering their properties, while the 3D printing technique is advantageous because of the customized manufacturing. Therefore, smart materials combined with 3D printing leads to a greater functionality of biomedical devices. Given that, these materials have been the center of attention in the biomedical field in recent years. This chapter introduces smart materials serving as biomedical materials, including environment-responsive hydrogels, self-healing hydrogels, shape memory polymers, and conductive polymers, as well as their applications in the biomedical field when combined with the 3D printing technique.