BCG may refer to:
Astronomy Blue compact galaxy, a type of galaxy undergoing an exceptionally high rate of star formation Brightest cluster galaxy, the brightest in a cluster of galaxies
Medicine and biochemistry BCG vaccine (Bacillus Calmette–Guérin), for tuberculosis Ballistocardiography, measuring heart forces Bromocresol green, a dye and pH indicator
Companies Beijing Capital Group, a Chinese state-owned real estate company Boston Consulting Group, a global management consulting firm Buffalo Creek and Gauley Railroad (BC&G, 1904-1965), from Dundon to Widen in Clay County, West Virginia, US
Other uses BCG matrix, for product line analysis Billy Gillispie, American basketball coach Bolt, carrier group in a firearm British Comedy Guide Big City Greens, a Disney animated series "Birth control glasses", common dysphemism for GI glasses