The gulf darter (Etheostoma swaini) is a small freshwater fish in the family Percidae. It can be found in Louisiana, Mississippi, Alabama, Florida, Tennessee, and Kentucky. It is a colorful fish, males having vertical barring of red-orange and blue-green near the tail, growing to a length of about 7.8 centimeters (3.1 in). It is typically found in small and medium-sized creeks, often in very shallow water. It occurs over sandy bottoms and among aquatic vegetation such as Sparganium americanum, foraging among the plants and organic debris for insect larvae and small invertebrates. The International Union for Conservation of Nature has assessed its conservation status as being of "least concern".