In this study, gold nanoparticle (AuNP)-modified carbon paste electrode (CPE)-based electrochemical sensor for hyaluronic acid (HA) detection was developed. The change in the electrode surface area and the increase in HA electrochemical signals after modification with AuNP were investigated. Afterwards, pH and scan rate effects on developed HA sensor response were extensively studied and analytical characteristics were examined. As a result, limit of detection and limit of quantification values of developed sensor were found as 0.0034 mg/100 mL HA and 0.0115 mg/100 mL HA, respectively. Meanwhile, reproducibility and relative standard deviation values for 0.08 mg/100 mL HA were also calculated and found as 2.04% ( n  = 3). For the interference study, ascorbic acid, glucose, acetylcholine and H 2 O 2 were chosen as interfering substances, and in the presence of cocktail of these molecules, the recovery values were estimated as 102.79% (onefold) 97.88% (twofold) and 100.30% (threefold). Also, AuNP/CPE sensor was applied for HA detection in dermatological HA serum, sheet mask and hair serum. Acceptable recovery values varying between 99.86 and 100.70% were obtained with real samples, which shows the applicability of the developed sensor.