Throughout history, the common green turtle has been an important source of food to local human populations and sea voyagers.

The common green turtle was once abundant in all temperate and tropical seas of the world, but has become increasingly scarce in areas where it is commercially exploited for food and eggs; the demand for turtle soup, "turtle oil" for cosmetics, and turtle skin for shoe leather has encouraged a continuing, and sometimes illegal, trade. The common green turtle is still plentiful in Hawaii, but now rarely nests in North America, although feeding areas in Florida still have fairly large populations.

Common green turtles are almost exclusively herbivores, feeding on algae and sea grass. The adults may reach a carapace size of 1 m long (3 ft.) and a weight of 150 kg (330 lb.).

Female common green turtles can travel more than 2200 km (1,367 mi.) from their feeding grounds to reach their nesting grounds. The females regularly return to the same beaches, and in great numbers, to lay their eggs. The hatchlings weigh about 25 g (0.9 oz.) and are approximately 50 mm long (2 in.).

Major nesting sites remain in the Galapagos Islands and on Ascension Island in the south Atlantic. In Hawaii, the primary nesting site is at French Frigate Shoals, Honolulu. Brazil, Costa Rica, Peninsular Malaysia, the Philippines, and Indonesia maintain protected hatcheries and regulate the harvest of the species.