The article reviews the current scenario and future perspectives of alternative protein sources in aquafeed. Fish meal, the primary protein source for most commercially farmed aquatic species, faces availability and price challenges, leading to the exploration of alternative protein sources. The review examines the effects of various plant- and animal-derived protein sources on the health, welfare, and growth performance of major aquatic species. Plant proteins, such as soybean meal, corn gluten meal, and rapeseed meal, are widely used but can have anti-nutritional factors that affect growth and health. Animal by-products, including poultry and feather meals, meat and bone meal, and insect meals, offer high protein content and lack anti-nutritional factors but may have ethical concerns. The study highlights that the inclusion levels of these alternative proteins range from 10% to 80% and 2% to 100%, respectively, and can positively impact growth, feed conversion, and fillet quality. However, excessive inclusion can negatively affect growth and metabolic activities. The review suggests that combining different protein sources may yield synergistic effects and is expected to be the future of aquafeed formulation. Additional research is needed to fill knowledge gaps and develop sustainable and cost-effective alternatives.The article reviews the current scenario and future perspectives of alternative protein sources in aquafeed. Fish meal, the primary protein source for most commercially farmed aquatic species, faces availability and price challenges, leading to the exploration of alternative protein sources. The review examines the effects of various plant- and animal-derived protein sources on the health, welfare, and growth performance of major aquatic species. Plant proteins, such as soybean meal, corn gluten meal, and rapeseed meal, are widely used but can have anti-nutritional factors that affect growth and health. Animal by-products, including poultry and feather meals, meat and bone meal, and insect meals, offer high protein content and lack anti-nutritional factors but may have ethical concerns. The study highlights that the inclusion levels of these alternative proteins range from 10% to 80% and 2% to 100%, respectively, and can positively impact growth, feed conversion, and fillet quality. However, excessive inclusion can negatively affect growth and metabolic activities. The review suggests that combining different protein sources may yield synergistic effects and is expected to be the future of aquafeed formulation. Additional research is needed to fill knowledge gaps and develop sustainable and cost-effective alternatives.