Fish meal has been widely used as the main conventional protein source in aqua feeds. However, the dependence on fish meal is expected to decline due to the shortage in world production of fish meal, and increased demand for fish meal in feeds for livestock and poultry industries. Therefore, partial or total replacement of fish meal with less expensive, locally available alternative protein sources will become inevitable. Many attempts have been conducted alongside this line. The present review throws light on alternative dietary protein sources for aqua feeds, with emphasis on the most cost effective, commonly used sources, such as fishery by-products, terrestrial animal by-products, oilseed plants, aquatic plants, single cell proteins, grain legumes, plant protein concentrates and cereal by-products. The different processing methods involved in removing the ant nutritional compounds and improve the protein content in the plant protein sources.