Gab or GAB may refer to:

• Gáb, a cuneiform sign
• Gab (social network), an American social networking platform
• "Gab" (song), an Occitan boasting song of the Middle Ages
• Gab, Iran, a village in Hormozgan Province
• Games and Amusements Board, a Philippine sports and gambling regulatory government agency
• Georgia Academy for the Blind
• German American Bund, a German-American pro-Nazi organization (1936–1941)
• Government Accountability Board, a defunct (since 2016) Wisconsin political regulatory institution
• The Great American Bash, a professional wrestling event
• Great Artesian Basin, in Australia
• Great Australian Bight, an open bay
• Greater Atlantic Bank, a defunct American community bank