Madracis carmabi, n. sp. is a relatively common zooxanthellate scleractinian coral found throughout the Caribbean. The species is described based on colonies collected from Curaçao. Features that distinguish this species from other Madracis species are the combination of (1) a branching morphology, and (2) decameral septal organization. The species is mostly found between 20–40 m depth. Hybridization between Madracis decactis and Madracis formosa is proposed as a process leading to this new species following the principles of reticulate evolution.