The design and synthesis of novel hybrid‐silica nanoparticles (NPs) containing the FDA‐approved antimicrobial triclosan (Irgasan) covalently linked within the inorganic matrix for its controlled, slow release upon interaction, is reported. The NPs are in the range of 130 ± 30 nm in diameter, with a smooth and spherical morphology. Characterization of the hybrid‐silica NPs containing triclosan, namely T‐SNPs, and their appropriate linkers is accomplished by microscopic and spectroscopic techniques. Preliminary antimicrobial activity is studied through bacterial‐growth experiments. The T‐SNPs are found to be superior in killing bacteria, as compared with the free biocide.