<p>Municipal Solid Waste Incineration generates different byproducts, such as bottom ash, fly ash, and air pollution control residues. To divert ash from landfilling, which requires land areas and presents environmental risks, we need sustainable valorization routes that close material loops. The well-established presence of metal oxides and carbon-rich regions in the ash, prompted us to explore their valorization as sustainable electroactive materials, for a broad range of technologies, such as battery electrode formulations. Considering the heterogeneity of the elemental and mineralogical composition and physical structure of municipal solid waste incineration ash, we studied their electrical response through an integrated approach combining the characterization of their elemental and mineralogical composition, (surface) chemical state of the elements, structure, and electrical response. The elemental composition of the ash was determined using Instrumental Neutron Activation Analysis and the mineralogical composition by X-Ray Diffraction. The characterization of their surface chemical states was performed with X-ray Photoelectron Spectroscopy, which revealed the presence of several metal oxides and carbon atoms hybridized sp² structure in carbon-rich regions. Carbon was quantified by a CHNS/O analysis. Afterwards, we studied the morphology of ash samples by Scanning Electron Microscopy, with Energy Dispersive X-Ray Spectroscopy analysis. In ambient conditions, we deduced an electrical conductivity of&#xa0;10^–7&#xa0;S&#xa0;cm⁻¹ for pressed pellets of the ash.&#xa0;We propose that, besides their elemental and mineralogical composition, the knowledge of the electronic states of the atoms making up the ash is key for their valorization as sustainable electroactive functional materials.</p> Graphical Abstract <p></p>