In this work, bagasse derived nitrogen-doped activated carbon (B-dNAC) was prepared using waste sugarcane as a carbon precursor via a KOH-urea activated method. Then, gold nanoparticles were successfully loaded onto the B-dNAC and gold nanoparticles/B-dNAC nanocomposites (AuNPs/B-dNACNs) were obtained through the incorporation of chloroauric acid by a facile thermal reduction process. The structural composition and the morphology of the composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). A AuNPs/B-dNACNs modified glassy carbon electrode (AuNPs/B-dNACNs/GCE) was constructed. The electrochemical behavior of 4-aminophenol (4-AP) on the AuNPs/B-dNACNs/GCE was investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The AuNPs/B-dNACNs/GCE exhibited good electrocatalytic performance for the electrooxidation of 4-AP and can be used as a novel electrochemical sensor for the detection of 4-AP. Under optimal conditions, the linear range of 4-AP was 1–400 μM, with a low detection limit of 0.61 μM. In addition, it displayed good selectivity, reproducibility and stability. Most importantly, the AuNPs/B-dNACNs/GCE could be used for the determination of 4-AP in acetaminophen tablets, and good recovery was obtained in the range of 97.1%–104.9%.