The study represents a comprehensive exploration of the adsorption behavior and corrosion inhibition properties of a recently synthesized heterocyclic compound, known as Ind-NO2, derived from indazole, particularly focusing on its interaction with brass surfaces within a hydrochloric acid (HCl) environment. This research is pivotal in the field of corrosion protection as it addresses the crucial need for effective inhibitors to safeguard metal surfaces from deterioration in aggressive chemical environments. The primary objective of this study is to assess the efficacy of Ind-NO2 in preventing brass oxidation. To achieve this goal, a diverse array of experimental techniques is employed, each providing unique insights into the inhibition mechanism and adsorption characteristics of the compound on the brass surface. Electrochemical impedance spectroscopy (EIS) offers valuable information regarding the electrical properties and corrosion kinetics of the brass–Ind–NO2 system. Potentiodynamic polarization (PDP) analysis helps elucidate the electrochemical behavior of the brass surface in the presence of the inhibitor, aiding in understanding its ability to control the corrosion rate. Additionally, X-ray photoelectron spectroscopy (XPS) provides detailed insights into the chemical composition and bonding states of the adsorbed inhibitor molecules on the brass surface, offering molecular-level understanding. The results obtained from these experimental techniques demonstrate a significant inhibition efficiency of the Ind-NO2 compound, with a remarkable 90.5% reduction in corrosion rate observed. Moreover, analysis based on the Langmuir adsorption model reveals that the inhibitor molecules adhere to the brass surface in a monolayer effectively forming a protective barrier against corrosive attacks. Further insights into the morphology and composition of the protective film formed on the brass surface are obtained via supplementary analyses utilizing scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD). In summary, this investigation contributes valuable insights into the adsorption properties and corrosion inhibition mechanism of the novel heterocyclic compound Ind-NO2.