Marine-derived chitin and chitosan are vital renewable resources within the blue economy, yet traditional extraction methods often depend on environmentally detrimental solvents. This chapter reviews emerging green solvent systems—specifically ionic liquids, deep eutectic solvents, and alkali aqueous solutions—and their application in sustainable chitin/chitosan processing. It examines solvent design principles, dissolution mechanisms, and their effects on the physicochemical properties of the resulting materials. These green methodologies enable the creation of advanced products such as biomedical scaffolds, sustainable packaging, and water treatment membranes. Additionally, the chapter emphasizes lifecycle assessments to evaluate environmental impacts and resource efficiency while addressing scalability challenges. Recommendations for industrial implementation and future research directions are provided to overcome technical and economic barriers. By integrating innovative green chemistry strategies with comprehensive environmental evaluations, this work outlines a clear pathway toward transforming marine-based material processing in alignment with the blue economy’s objectives of ecological stewardship, resource optimization, and economic growth.