Owing to its advantages of ultrashort pulse width and extremely high peak intensity, ultrafast lasers have been widely used in fabricating plasmonic nanomaterials. Laser beams with extremely high power densities heat the free electrons in plasmonic nanomaterials, thereby increasing the lattice temperature and causing photothermal reshaping. Depending on the power density of the laser beam and the melting/boiling threshold, we review three types of photothermal reshaping mechanisms: complete melting above threshold, surface atom diffusion below melting temperature, and ablation. The exemplary applications of photothermal reshaping of plasmonic nanomaterials in optical data storage, plasmonic color printing, and steganography are reviewed.