A huge variety of plants are harvested worldwide and their different constituents can be converted into a broad range of bionanomaterials. In parallel, much research effort in materials science and engineering is focalized on the formation of nanoparticles and nanostructured materials originating from agricultural residues. Cellulose (40-50%), hemicellulose (20-40%), and lignin (20-30%) represent major plant ingredients and many techniques have been described to separate the main plant components for the synthesis of 2 nanocelluloses, nano-hemicelluloses, and nanolignins with divergent and controllable properties. The minor components, such as essential oils, could also be used to produce nontoxic metal and metal oxide nanoparticles with high bioavailability, biocompatibility, and/or bioactivity. This review describes the chemical structure, physical and chemical properties of plant cell constituents, different techniques for the synthesis of nanocelluloses, nanohemicelluloses, and nanolignins from various lignocellulose sources and agricultural residues, and the extraction of volatile oils from plants as well as their use in metal and metal oxide nanoparticles production and emulsion preparation. Further, details about the formation of activated carbon nanomaterials by thermal treatment of lignocellulose materials, few examples of mineral extraction from agriculture waste for nanoparticles fabrication and the emerging applications of plant-based nanomaterials in different fields, such as biotechnology and medicine, environment protection and remediation, or energy production and storage were also included. The review also briefly discusses the recent developments, toxicity, regulations, and challenges of nanomaterials obtained from plant residues.