Here, we demonstrate the development of a hydrazine sensor using gold nanoparticles (AuNPs) electrodeposited on the surface of a glassy carbon electrode (GCE) modified with the material composite of graphene oxide (GO) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The morphological, electrochemical, and structural properties of this developed hydrazine sensor were characterized by Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Cyclic voltammetry and amperometry techniques have been used to investigate the electrochemical behavior and electroanalytical performance of this proposed sensor, and obtained an excellent result in terms of its analytical parameters. A linear range of 0.2−100 μM was obtained from the amperometric detection of hydrazine using this developed sensor. The detection and quantitation limits of this proposed hydrazine sensor were calculated as 0.005 and 0.08 μM, respectively. Furthermore, this proposed sensor for hydrazine detection exhibited good reproducibility and stability with a relative standard deviation (%RSD) of less than 5%. In addition, this developed sensor for hydrazine detection also exhibited good selectivity in the presence of several interferences, including NaNO2, FeSO4, Zn(CH3CO2)2, NH4NO3, chlorophenol, triclosan, and ascorbic acid, as well as it depicted %recovery values of 93–104%. In conclusion, this platform sensing based on a AuNPs/GO/PEDOT:PSS-modified GCE for hydrazine detection shows excellent electroanalytical performance and could potentially be employed for real applications.