In this study, a fluorescent ethanol sensor is developed to determine the ethanol concentration in the liquid phase. The sensor is developed using a complex of resazurin (RA)/resorufin (RO) and a hydrotalcite (HT) catalyst in a sol-gel matrix of methyltrimethoxysilane (MTMS) to produce a fluorescent ethanol-sensing membrane (RA/RO*HT membrane). The operation mechanism of the RA/RO*HT membrane is based on (i) the oxidation of ethanol to acetaldehyde and (ii) the reduction of RA to RO, through electron flows followed by EtOH ↔ HT ↔ RA/RO ↔ EtOH interactions. These possible redox reactions can lead to an increased fluorescence intensity of the RA/RO*HT membrane as the ethanol concentration increases. The RA/RO*HT membrane shows a linear detection range of 1–20 vol.% EtOH with limit of detection (LOD) of 0.178%. Additionally, the RA/RO*HT membrane has high sensitivity and accuracy for determining the alcohol content in several Korean alcoholic beverages.