The development of nanotechnology has enabled unprecedented manipulation of light and control over its interaction with matter in various engineered nanophotonic systems. This session focuses on experimental implementation and numerical modeling of light-matter interaction in various photonic/plasmonic metastructures, leading to enhanced performance metrics and new applications of metamaterials, metasurfaces, metallic and dielectric nanoantennas, as well as plasmonic nanostructures. Preferred topics include light-matter interaction in strong coupling regime, quantum-light sources, quantum nanophotonics, nonlinear optics in photonic/plasmonic meta-structures, novel optical devices, polariton lasers, light-emitting metasurfaces, random lasers, lasing spasers, etc.