The engineering of high-performance functional nanomaterials for efficient monitoring of Vitamin-C/Ascorbic Acid (AA) is highly desirable in the food, chemical, cosmetics, and pharmaceutical industries. In this regard, this report presents the engineering of novel cerous sulfate Ce2(SO4)3 nanoflowers, decorated reduced graphene oxide (rGO) through an economic, energy-efficient and rapid one-pot hydrothermal strategy for electrochemical detection of AA. The obtained nanocomposite demonstrates the successful formation of nano Ce2(SO4)3 with flower morphology having large surface area and potential to promote the electrolyte accessibility as well as electronic transmission during sensing phenomenon. The Ce2(SO4)3/rGO (CSG) nanoflower composite was drop casted on screen printed carbon electrode (SPCE) and tested for its electrochemical detection of AA. At +0.337 V, a well-defined oxidation peak of AA occurred in phosphate buffer solution of pH 7. A linear response of the CSG electrode was further obtained under optimum conditions, for the AA concentration range of 10 − 1000 μM with a sensitivity of 0.2973 μA μM−1cm−2 and lowest detection limit of 900 μM. The excellent Vitamin-C sensing ability of CSG is attributed to the synergistic effect from the dimensional anisotropy of flower-like morphological features of Ce2(SO4)3 as well as the interfacial structure. The CSG was also tested for vitamin C tablets, VeeCee-Z, to validate its commercial applicability. Furthermore, fabricated electrochemical sensor exhibited significant reproducibility (98.63%) and optimum stability. Thus, the significant findings of this work are believed to hold the prospect for sensitive and prompt determination of Vitamin-C in the industrial domains.