The American crocodile (Crocodylus acutus) is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida, the Caribbean islands of Cuba, Jamaica, and Hispaniola, and the coasts of Mexico to as far south as Peru, Ecuador, Colombia, and Venezuela.

The habitat of the American crocodile consists largely of coastal areas. It is also found in river systems, but tends to prefer salinity, resulting in the species congregating in brackish lakes, mangrove swamps, lagoons, cays, and small islands. Other crocodiles also have tolerance to saltwater due to salt glands underneath the tongue, but the American crocodile is the only species other than the saltwater crocodile to commonly live and thrive in saltwater. They can be found on beaches and small island formations without any freshwater source, such as many cays and islets across the Caribbean. They are also found in hypersaline lakes; one of the largest known populations inhabits Lago Enriquillo in the Dominican Republic.

The American crocodile is one of the largest crocodile species. Males can reach lengths of more than 7 m (23 ft 0 in), weighing over 1,000 kilograms (2,200 lb). On average, mature males are more in the range of 2.9 to 4.1 m (9 ft 6 in to 13 ft 5 in) in length weighing up to about 400 kg (880 lb). As with other crocodile species, females are smaller, rarely exceeding 3.8 m (12 ft 6 in) in length even in the largest-bodied population.

Like any other large crocodilian, the American crocodile is potentially dangerous to humans, but it tends not to be as aggressive as some other species. American crocodiles coexist with the American alligator in Florida, and with the smaller spectacled caiman within Central America and South America. The IUCN lists the American crocodile as vulnerable, and is a federally threatened, flagship species and ecological indicator within the Florida Everglades World Heritage Site.

The American crocodile was described by Georges Cuvier in 1807, and became known as the "sharp-snout alligator". In 1822, Constantine Samuel Rafinesque postulated that the species was in fact a crocodile.

The species was redescribed as Crocodylus floridanus by William Temple Hornaday in 1875, when Hornaday and C. E. Jackson were sent to Florida to collect alligator hides. Upon hearing of a "big old gator" in Arch Creek at the head of Biscayne Bay, Hornaday and his companions searched for it and reported:

In a few hours, we got sight of him, out on the bank in a saw-grass wallow. He was a monster for size—a perfect whale of a saurian, gray in color—and by all the powers, he was a genuine crocodile!

Crocodylus floridanus is now considered an invalid junior synonym of C. acutus.