HCB may refer to:
- Hexachlorobenzene, a fungicide formerly used as a seed treatment
- Henri Cartier-Bresson, a French photographer considered to be the father of modern photojournalism
- HCB (classification), a Paralympic cycling classification
- Hampshire Cricket Board, the governing body for all recreational cricket in the historic county of Hampshire
- Hydrocarbonoclastic bacteria, a form of oil biodegrader
- Hackbridge railway station, a railway station at Hackbridge in South London
- Hamptons Collegiate Baseball, a summer baseball organization located in The Hamptons, New York