© 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.In this study; an easy, practical, and selective sensor has been developed for the electrochemical determination of riboflavin. To prepare the modified electrode, the gold nanoparticle was deposited on the pencil graphite electrode (AuNP/PGE) by the method of chronoamperometry at -3.0 V for 30 s in 0.5 M H2SO4 solution containing 10 mM tetrachloroaurate. Functionalized multi-walled carbon nanotube (f-MWCNT) solution was dropped on prepared AuNP/PGE and the functionalized multi-walled carbon nanotube/gold nanoparticle/pencil graphite electrode (f-MWCNT/AuNP/PGE) was prepared for measurements. Characterization studies of the prepared sensor were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) methods. The surface morphology of the prepared sensor was investigated by field emission scanning electron microscopy (FESEM). Differential pulse voltammetry (DPV) was used to carry out electrochemical measurements in phosphate buffer solution pH 4.0. Limit of detection (LOD) and limit of quantitation (LOQ) values were found to be 0.0352 and 0.118 μmol l-1, respectively. The fabricated sensor showed excellent anti-interference ability against ascorbic acid (AA) and glucose (G). The applicability of the constructed sensor to real samples was investigated and good recovery values were achieved. As a result, it has been seen that the modified electrode is applicable in applications of riboflavin determination.