This chapter describes structures, production principles and applications of three-dimensional (3D) knitted textiles. It begins with an introduction to 3D knitted textiles, including classification and main applications. Then three types of 3D knitting technologies are introduced. Four typical 3D knitted structures including tubular, net-shape, spacer and directionally oriented structures are described in terms of the structure feature and production process. The applications of typical 3D knitted textiles are also discussed. Finally, the future development trends of 3D knitted textiles are prospected.