Solar-driven interfacial evaporation (SDIE) is emerging as a promising pathway to solving the worldwide water shortage and water pollution. Nanomaterials (e.g., plasmonic metals, inorganic/organic semiconductors, and carbon nanomaterials) and related nanochemistry have attracted increasing attention for the solar-to-vapor process in terms of broadband absorption, electronic structure adjustment, and surface/interface chemistry manipulation. Furthermore, the assembly of nanomaterials can contribute to the mass transfer, heat management, and enthalpy regulation of water during solar evaporation. To date, numerous nano-enabled materials and structures have been developed to improve the solar absorption, heat management (i.e., heat confinement and heat transfer), and water management (i.e., activation, evaporation, and replenishment). In this review, we focus on a systematical summary about the composition and structure engineering of nanomaterials in SDIE, including size and morphology effects, nanostructure optimizations, and structure-property relationship decoupling. This review also surveys recent advances in nanochemistry (e.g., preparation chemistry and structural chemistry) deployed to conceptual design of nanomaterials. Finally, the key challenges and future perspectives of nanomaterials for solar evaporation are overviewed. This review aims at providing guidance for the design and construction of nanomaterials for high-efficiency SDIE on the basis of the aspects of materials science and chemical engineering.