The Kemp's Ridley is the smallest of the sea turtles, with the weight of an adult generally being less than 45 kg (100 lb.) and the straight-line carapace length around 65 cm (26 in.).

Nesting occurs from April to July, and the hatchlings weigh 15 to 20 g (0.5 to 0.7 oz.). They range from 42 to 48 mm (1.6 to 1.9 in.) in straight-line carapace length, and they are almost as wide as they are long. The young feed on brown algae called sargassum or gulfweed, but after a few years (1 to 5 years) they become largely crab-eaters.

Although the Kemp's Ridley can be seen from Nova Scotia to Mexico and occasionally in Europe, it occurs mainly in coastal areas of the Gulf of Mexico and the northwestern Atlantic Ocean.

The major nesting beach is on the north-eastern coast of Mexico, mainly just north of Tampico near Rancho Nuevo in the state of Tamaulipas. Because they depend on this one location, the population is very vulnerable. Their numbers have declined dramatically since 1947, when as many as 40 000 nesting females used to crowd the beach in a single day.

The big threat to Kemp's Ridley today is no longer the capture of females for food and leather, nor the coyotes or egg hunters that brought about the original decline: the main factor is now their incidental catch by shrimp trawlers.