BBO may stand for:

• Barium boron oxide, another name of barium borate
• Big Bang Observer, planned space gravitational wave observatory
• IATA code for Berbera Airport
• "BBO (Bad Bitches Only)", a song by Migos featuring 21 Savage, from the album Culture II
• Beta barium borate (β-BaB₂O₄) crystal
• Black Bag Operations
• Bundesbahn Österreich, a former name for the Austrian Federal Railways
• Bureau Bijzondere Opdrachten, a Dutch secret service during World War II
• The Bridge Base Inc. web site Bridge Base Online
• British Ballet Organization, a dance teaching and examination board
• Broome Bird Observatory
• BBO, the ICAO code for Flybaboo
• Bottom Bottle Opener, a cap-shaped indentation found in the bottom of Miller High Life bottles in the late 1980s which could be used to open other bottles of Miller High Life.
• Best Bid Offer, a type of financial quote that includes the best bid and ask (offer) prices

• Legipont, Oliver
• Leg iron
• Le Girouard
• Legisign
• Legislated Employment Equity Program
• Legislate from the bench
• Legislation enacted by the Eighth Parliament of Solomon Islands
• Legislation No. 4000 of 1958
• Legislation of cannabis
• Legislation of Casimir the Great
• Legislation of cyberstalking
• Legislation of marijuana
• Legislation of the Provisional Government of Hong Kong
• Legislations of the Provisional Government of Hong Kong
• Legislation sponsored by Ron Paul
• Legislative Affairs Office
• Legislative Assemblies in states of India
• Legislative Assemblies of Brazilian states
• Legislative assemblies of the Roman Empire
• Legislative Assemblies of the Roman Kingdom
• Legislative Assembly area
• Legislative assembly (disambiguation)
• Legislative Assembly of Amazonas
• Legislative Assembly of Andhra Pradesh
• Legislative Assembly of Arunachal Pradesh