Recent advances in the properties, synthesis, modifications and applications of one-dimensional single-crystalline Ti–O based nanostructures (including nanotubes, nanobelts, nanowires, and nanorods) are reviewed. The physical and chemical properties of one-dimensional nanostructured titanates, such as adsorption, stability, ion-exchange, optical, and proton conductivity properties, are described in connection with a particular application. The experimental parameters, morphologies, and mechanism of formation of one-dimensional nanostructured titanates produced by the alkaline hydrothermal method are critically discussed. Current progress in the modifications of one-dimensional single-crystalline Ti–O based nanostructures are discussed together with their improved performances. Examples of applications of one-dimensional nanostructured titanates in photocatalysis, lithium batteries, sensors, hydrogen production and storage, solar cells and biomedicine are presented.