A fluorescence chemosensor HBC ((E)‐3‐((2‐hydroxybenzylidene)amino)benzofuran‐2‐carboxamide) for detection of Zn2+ was designed by the condensation combination of 3‐aminobenzofuran‐2‐carboxamide and salicylaldehyde. Sensor HBC showed an excellent selective “off–on” fluorescent response toward Zn2+. Detection limit (1.08 μM) for Zn2+ was much lower than the WHO standard (76.0 μM). Importantly, HBC could recognize and quantify Zn2+ in real samples and live cells. Detection process of HBC for Zn2+ was explained by ESI‐mass, Job plot, UV–Vis and 1H NMR titrations, and theoretical calculations.