Olive ridleys get their name from the coloring of their heart-shaped carapace (shell), which starts out grey but reaches an olive green once the turtles are adults.

Their shells are made up of a large number of vertebral and coastal scutes (bony plates) that are nearly circular. Olive ridleys are different from other sea turtle species in that the number of coastal scutes varies from one habitat to another. They have one to two visible claws on each of their paddle-like flippers. Relatively small-headed, they are also small of body—one of the smallest sea turtle species. Their bodies will measure only between 24-28" in length and will weigh less than 100 lbs. The turtle they most resemble is their close relative, the Kemp's ridley turtle.

Olive ridleys inhabit tropical and subtropical coastal bays and estuaries in the eastern Pacific, Indian, and Atlantic oceans. Olive ridleys appear to be nomadic, using multiple feeding grounds and having no defined migratory routes. Omnivorous, they feed in waters up to 500 feet deep. With their powerful jaws, they consume a varied diet: bottom-dwelling crustaceans, mussels, fish, jellyfish, crabs, shrimp, and mollusks.

The olive ridley's life span is believed to be between 50 and 60 years. They reach reproductive maturity at 10 to 15 years of age, and are reproductively active for nearly 21 years.

Olive ridley nest (lay their eggs) in large groups of females called arribadas or arribazones (a derivation of the Spanish word for "arrival"). In preparation for the arribada, females gather off the coast, and then emerge to nest together ashore. In the past, as many as one million nesting females have been seen during an arribada that spanned several days on the same beach. Today, olive ridley arribadas consist of, at most, a few thousand nesting females.

The main nesting grounds are on the shores of the Pacific Ocean around Costa Rica, Mexico, Nicaragua, and the Northern Indian Ocean, where the turtle nests abundantly in eastern India and Sri Lanka. Olive ridleys nest two to three times per nesting season, which occurs every one to two years. Nesting, which always occurs at night, takes between 45 minutes to an hour, after which time the female ridleys return to the ocean and disperse in many different directions. Depending on geographic location, nesting occurs from June to December, peaking in September and October. Each nest contains about 110 eggs. After a 55-day incubation, hatchlings emerge from the nests small—about 1.5" long and weighing less than an ounce—and are black with greenish sides.

Of all the sea turtles, olive ridley populations are relatively healthy. Still, there are so few left that in 1978, the U.S. Endangered Species Act (ESA) listed the Mexican nesting populations of olive ridleys as endangered—and all others throughout the world as threatened. Despite this action, olive ridley populations have actually shown a decline in abundance since their ESA listing as threatened, and at this time, the International Union for Conservation of Nature and Natural Resources (IUCN) lists all populations of olive ridleys as endangered. Olive ridleys are also listed on Appendix I of the Convention on International Trade in Endangered Species of Fauna and Flora (CITES), which means that trade in olive ridleys, their eggs or any part or product derived from the turtle is forbidden.

Olive ridleys suffer high mortality rates from gill nets and trawl fisheries. They also fall victim to water pollution. Adding to these environmental hazards, the olive ridley is jeopardized by trade, too: highly prized in Japan for its meat and eggs, the turtle is illegally hunted to supply this trade. Finally, occasionally on beaches where arribadas occur, there is a natural breakdown of nest contents, which creates fungus and bacteria that destroys the buried sea turtle eggs. This natural occurrence contributes to large discrepancies in olive ridley populations from year to year.