Luminescent core–shell nanoparticles (NPs) with crosslinked aggregation‐induced emission (AIE) core structures, which exhibited excellent emission independent of the dispersion state of the NPs, have been developed by a facile one‐pot method based on the self‐assembly of an amphiphilic block copolymer poly(PEGMA)‐b‐poly(DB3VT). Core–shell micelles with a poly(DB3VT) core were formed from poly(PEGMA)‐b‐poly(DB3VT) in tetrahydrofuran (THF)/H2O condition, and the crosslinked AIE‐based structure was selectively incorporated into the core by the Suzuki coupling reaction between poly(DB3VT) blocks and tetraphenylethylene (TPE)‐based coupling monomers at the same time. This method afforded a uniform NP with a crosslinked TPE‐based AIE core structure. The obtained NP exhibited excellent emission both in diluted solution and solid states. This result indicated that the formed TPE‐based AIE core structure was always aggregated regardless of NP dispersion owing to the crosslinking as we expected. The crosslinked TPE‐based AIE core structure, which was related to the emission property, was readily tuned by the selection and combination of coupling monomers in the Suzuki coupling reaction. By incorporating electron‐deficient units into the core, the emission color could be successfully tuned from yellow‐green to orange and red while maintaining the emission property independent of the state of the NP dispersion. These results demonstrated that NPs with the crosslinked AIE core structures are a promising luminescent material design motif to realize emission independent on molecular dispersion.