Lignocellulosic biomass, rich in cellulose, hemicellulose, and lignin, represents a promising renewable resource. However, lignin, a complex polyphenolic material, remains underutilized despite its surplus production. This review focuses on the conversion of lignin into macromonomers for polymer production. While lignin's potential in polymer science is gaining recognition, studies focusing specifically on lignin-based macromonomers remain limited. This review addresses this gap by discussing the synthesis of lignin macromonomers and their role in polymer synthesis. It also highlights the potential and challenges of sourcing lignin from agri-food waste, with the goal of inspiring advancements and fostering innovation in the development of more sustainable and circular polymer systems.