AbstractOrganic–inorganic hybrid superlattices (OIHSLs) hold attractive physical and chemical properties, while the construction of single‐crystal covalent OIHSLs has not been achieved. Herein a coordination assembly strategy was proposed to create a single‐crystal covalent OIHSL PbBDT (BDT=1,4‐benzenedithiolate), where layered [PbS2] sublattice covalently connects with benzene sublattice. The covalent bonding offers better thermo‐/chemi‐stability, inter‐sublattice electron transport, and unique organic‐group‐functionalized surface, which may enable better performances in chemical applications than non‐covalent OIHSL. These features endow PbBDT with the highest sensitivity, the lowest detection limit and excellent selectivity towards NO2 at room temperature among all chemiresistive gas‐sensing materials with reported response time less than 2 min without the need of light assistance.