Nonwoody lignin, derived from abundant agricultural residues and forestry by-products, offers a sustainable and cost-effective precursor for carbon materials in supercapacitors. This chapter reviews and consolidates recent progress in converting nonwoody lignin into high-performance carbon electrodes for electrochemical energy storage, with emphasis on electric double-layer capacitors (EDLCs), pseudocapacitors, and hybrid configurations. The influence of tailored extraction, purification, and activation routes (for example, organosolv and alkaline pretreatment, followed by pyrolysis and chemical or physical activation) on the resulting carbon microstructure, porosity, and heteroatom functionality is discussed, along with how these features govern ion transport, charge storage sites, and redox activity. Key performance metrics relevant to nonwoody lignin-derived carbons include specific capacitance, rate capability, power density, energy density, and cycling stability (percentage retention after thousands of cycles). Compared with conventional activated carbons and some carbon nanotube/graphene-based electrodes, lignin-derived carbons can exhibit competitive surface areas, tunable pore architectures, and enhanced chemical functionality that promote both EDLC and pseudocapacitive contributions. Challenges remain in achieving reproducible feedstock quality, scalable processing, and energy-efficient activation while minimizing environmental impact. The design principles linking lignin structure to electrochemical performance, such as preserving mesoporosity for fast ion diffusion, optimizing conductivity, and controlling surface groups that enable mild pseudocapacitive behavior, are highlighted in this chapter. Finally, a roadmap is outlined for advancing nonwoody lignin-derived electrodes from lab-scale demonstrations to scalable, sustainable devices capable of delivering high power without sacrificing cycle life.