Raman spectroscopy (RS) is presented as a non-destructive, label-free analytical platform for the identification and characterization of microplastics of a size ranging between 1 μm and 5 mm, and nanoplastics, having a size less than 1 μm in diverse environmental and biological matrices. The chapter details the physical principles and instrumentation of different Raman methods such as micro-Raman spectroscopy, confocal Raman mapping and surface-enhanced Raman spectroscopy (SERS) and summarizes their application in water, sediment, soil, air, and tissue samples when coupled with microscopy, image analysis and chemometric workflows. The evidence from literature demonstrates polymer fingerprinting (for polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, polyamide and others), particle-level metrics like size, abundance, spatial distribution, crystallinity and routine detection in lower micrometer range. SERS and laboratory-scale tip-enhanced approaches extend sensitivity toward nanoscale but remain largely non-routine. Fluorescence and pigment interference altered spectra by weathering and biofouling, limited throughput for hyperspectral mapping, and the absence of harmonized reference libraries are the persistent barriers identified. Recent changes were surveyed, which included portable instruments, automated high-throughput mapping, and artificial intelligence and/or machine learning classifiers. Coordinated standardization, expansion of aged/biofouled spectral libraries and validated, automated AI-assisted pipelines are necessary to translate Raman methods into scalable, reproducible microplastic monitoring.