This review article by Sunita Gaikwad and Mi Jeong Kim explores the extraction of collagen from fish by-products using various methods, including acid-soluble collagen (ASC), enzyme-soluble collagen (ESC), ultrasound extraction, deep eutectic solvent (DES) extraction, and supercritical fluid extraction (SFE). The authors highlight the importance of optimizing extraction parameters such as time, temperature, solid-to-liquid ratio, and solvent/pepsin concentration to maximize collagen yield and quality. The review also discusses the diverse applications of fish collagen in the biomedical sector, such as wound healing, tissue engineering, drug delivery, and cell culture, as well as its use in the food and cosmetic industries. Despite the potential benefits, challenges remain, including the low melting and denaturation temperatures of marine collagen, which limit its widespread application. The authors conclude by emphasizing the need for further research to enhance the physicochemical properties of fish collagen and explore novel combination strategies to meet the diverse requirements of different applications.This review article by Sunita Gaikwad and Mi Jeong Kim explores the extraction of collagen from fish by-products using various methods, including acid-soluble collagen (ASC), enzyme-soluble collagen (ESC), ultrasound extraction, deep eutectic solvent (DES) extraction, and supercritical fluid extraction (SFE). The authors highlight the importance of optimizing extraction parameters such as time, temperature, solid-to-liquid ratio, and solvent/pepsin concentration to maximize collagen yield and quality. The review also discusses the diverse applications of fish collagen in the biomedical sector, such as wound healing, tissue engineering, drug delivery, and cell culture, as well as its use in the food and cosmetic industries. Despite the potential benefits, challenges remain, including the low melting and denaturation temperatures of marine collagen, which limit its widespread application. The authors conclude by emphasizing the need for further research to enhance the physicochemical properties of fish collagen and explore novel combination strategies to meet the diverse requirements of different applications.