A crucial optical phenomena in photonics and optoelectronics fields, optical modulation techniques have received increasing demand for use in various applications, particularly in all-optical communications, interconnect, signal processing ultrafast information processing, optical data transmission, and high-performance computing. The development of high-performance light modulators has become essential as the current existent technologies cannot meet the increasing demand for compact, efficient, fast, and broadband optical modulators. To meet these challenges nanomaterials, which have strong nonlinear optical properties, have been used to fabricate optical modulators owing to their capability to modulate light with superior performance. The chapter presents an overview of the recent advancement in the development of optical modulators by utilizing one-dimensional (1D) and two-dimensional (2D) nanomaterials. This chapter firstly provides a brief explanation on the fundamental and operational principles of optical modulators, particularly on the all-optical modulator. This is followed by the properties and advantages of using 1D and 2D materials as optical modulators. Next, the typical approaches for 1D and 2D materials-based optical modulator including electro-optic approach, all-optical approach, and magneto-optic effect approach are discussed. Finally, at the end of this chapter the current challenges, prospects of these 1D- and 2D-based optical modulators for possible applications, and designing next-generation advanced devices in favor of commercialization are highlighted.