Protein-rich distillers dried grains (DDG) from ethanol plants has been used as livestock feed for many years. Feed conversion efficiency in fish, however, is typically much higher compared to traditional livestock. But, the cost of fish feed is one of the challenges for profitable fish cultivation. Due to the exponential growth of ethanol plants in recent years, DDG is becoming readily available as a reasonably-priced base material for animal feeds, and because it has a relatively high protein content, it also has much potential for use as a fish feed ingredient. Even though much literature is available on conversion of DDG into livestock feeds, very little work has been done on utilizing DDG as material for fish feed. Fish feed requires very different physical and functional properties compared to other animal feeds; these are generally achieved via extrusion technologies. Many researchers have investigated the effects of extrusion processing parameters on the resulting quality of food and feed products. Therefore, the objective of this study was to review nutrient requirements and feeding studies on inland fish cultivation, the effects of extrusion processing parameters and the resulting properties of extruded fish feed products, and the potential for utilizing DDG as a base material for fish feed production through extrusion technology. This review will bolster efforts aimed at increasing the value of DDG as a coproduct from the ethanol industry.