Elkhorn coral (Acropora palmata) is a large, branching coral with thick and sturdy antler-like branches. It is a member of the Acropora genus, the most abundant and species-rich group of corals in the world.

Colonies of Elkhorn coral are fast growing - branches increase in length by 2-4 inches (5-10 cm) per year, with colonies reaching their maximum size in approximately 10-12 years. Over the last 10,000 years, elkhorn coral has been one of the three most important Caribbean corals contributing to reef growth and development, as well as providing essential fish and marine invertebrate habitat.

While once the most abundant stony coral on shallow reef crests and fore-reefs of the Caribbean and Florida reef tract, by the early 1990s elkhorn coral had experienced widespread losses through its range. Multiple factors are thought to have contributed to coral declines, including impacts from hurricanes, coral disease, mass coral bleaching, climate change, coastal pollution, overfishing, and damage from boaters and divers. In 2006, elkhorn coral and a close relative, staghorn coral (Acropora cervicornis) were listed as threatened under the US Endangered Species Act.