Natural dyes are widely available from various sources, including plants, minerals, animals, insects, and microorganisms. Compared to synthetic dyes, they are generally biodegradable, non-carcinogenic, and non-toxic, with reduced effluent discharge and minimized harm to ecosystems. In textile applications, natural dyes provide brilliant colors and added functional benefits, such as UV protection, antioxidant and antimicrobial activities, and lower allergenic potential. However, their use in the textile sector is constrained by the significant quantities required and their lower affinity for textile fibers, making mordants essential for enhancing dye fixation and color vibrancy. Renewable biomordants, including tannin-rich compounds and oil-based mordants, are emerging as alternatives to traditional salt-based options. Both natural dyes and biomordants can be derived from renewable residue feedstock. Nonetheless, these sustainable approaches face challenges, such as the variability and availability of raw materials, cost-effectiveness, and efficient dyeing procedures. Despite these challenges, many dyes and mordants currently available in the textile market are sourced from renewable residues within a circular and carbon economy. This chapter reviews the development and application of renewable residue-derived dyes and mordants, emphasizing their potential to advance sustainability in textile production.