The Ouachita map turtle (Graptemys ouachitensis) is a species of turtle belonging to the family Emydidae.
This species is endemic to the United States. It can be found in Texas, Louisiana, Mississippi, Alabama, Oklahoma, Kansas, Arkansas, Missouri, Iowa, Minnesota, Wisconsin, Indiana, Ohio, West Virginia, Illinois, Tennessee and Kentucky. G. o. sabinensis exists only in the Sabine River of Louisiana and Texas. Both G. o. ouachitensis and G. o. sabinensis are freshwater riverine turtles. The G. o. ouachitensis is rarely seen on land unless it is nesting season or it is basking.
This species' carapace features a row of low vertebral spines, and is serrated on the posterior rim. The carapace is olive, dark brown, or black in coloration with light yellowish markings with dark borders. The plastron color varies from cream to yellow and is patterned with dark lines and swirls. The body color is grayish brown to blackish and is marked with yellowish stripes.
On the head, it has light yellow spots: a rectangular one behind each eye, an oval under each eye, and a round one on each side of the jaw. In some specimens, the spot behind and the spot under the eye can combine to form a single thick "C" stain. The eye has a black stripe in the middle.
Males are significantly smaller than females. The males can grow to be as large as 5 in (12 cm) in carapace length. The females can grow to be up to 10 in (25 cm) in carapace length.