A new labrid fish, Halichoeres burekae, is described from specimens collected at Stetson Bank, Flower Garden Banks National Marine Sanctuary (FGBNMS), in the northwestern Gulf of Mexico over claystone, sponge, and coral substrata. The bright purple, blue-green, and yellow body coloration, and anterior black pigmentation of the dorsal fin in the terminal male, large black irregular spot at the base of the caudal peduncle, salmon body coloration, yellow snout in the initial stage/female, and diagnostic differences in the mitochondrial DNA cytochrome b gene separate this species from all other western Atlantic labrids. Adult H. burekae were observed in small schools along the reef crest mixed with Thalassoma bifasciatum and Chromis multilineata, and small juveniles were observed in mixed schools with juvenile Clepticus parrae. It feeds primarily on calanoid copepods and other plankton and is a close relative of H. socialis from Belize. This species is currently known from the FGBNMS and reefs off Veracruz, Mexico, in the western Gulf of Mexico.