BG or bg can refer to one of several things:

• abbreviation for "background". Background image- "send me the updated "BG".
• BG Group, owners of the British Gas trademark
• The B.G. ("The Baby Gangsta"), an rapper formerly of the Cash Money label.
• Backgammon
• background as for art (in particular traditional animation).
• Baldur's Gate, a role-playing computer game and a city in the fictional Forgotten Realms setting.
• Berry Gordy, founder and former CEO of Motown Records.
• Blaenau Gwent, a county borough in Wales
• Blind Guardian, German power-metal band
• Boris Grebenshchikov, Russian singer and poet, leader of Aquarium band
• Bulgaria (ISO country code, BG)
• Bulgarian language (ISO 639 alpha-2, bg)

• the IATA code for Biman Bangladesh Airlines