| S/NO | Abbr. | Meaning |
| 1 | BO | Bachelor of Oratory |
| 2 | BO | Back Office |
| 3 | B/O | Back Order |
| 4 | BO | Back Order |
| 5 | BO | Back Orifice (trojan horse utility) |
| 6 | BO | Bad Order |
| 7 | BO | Banco de Occidente (Spanish: Western Bank; Honduras) |
| 8 | BO | Bang and Olufsen |
| 9 | BO | Barack Obama (44th US president) |
| 10 | BO | Barrel of Oil (oil and gas exploration) |
| 11 | BO | Barring Order |
| 12 | BO | Base Order |
| 13 | BO | Base-Out Prism |
| 14 | B/O | Battery Operated |
| 15 | BO | Battery Operated |
| 16 | BO | Battle Operations |
| 17 | BO | Battle Orders (Diablo 2 game) |
| 18 | B/O | Bearer Only |
| 19 | BO | Bearing Observed |
| 20 | BO | Beat Oscillator |
| 21 | BO | Belarus |
| 22 | BO | Bench Order |
| 23 | BO | Beneficial Occupancy |
| 24 | BO | Benefits Office |
| 25 | B/O | Best Offer |
| 26 | BO | Best Offer |
| 27 | BO | Biarritz Olympique (French rugby team) |
| 28 | BO | Big O (anime) |
| 29 | BO | Bilans Otwarcia (opening balance) |
| 30 | BO | Billing Official (US DoD) |
| 31 | BO | Binary Option (trading) |
| 32 | BO | Binary Output |
| 33 | BO | Binary to Octal |
| 34 | BO | Biodiversity Offsetting (conservation) |
| 35 | B/O | Biological Opinion |
| 36 | BO | Biological Opinion |
| 37 | BO | Bit Oxide |
| 38 | BO | Black Ore (Lineage 2 game) |
| 39 | BO | Black Organization (Detective Conan) |
| 40 | BO | Blackout |
| 41 | BO | Bloc Opératoire (French: Operating Room) |
| 42 | BO | Blocked Out |
| 43 | BO | Blocking Oscillator |
| 44 | B/O | Blocking Oscillator |
| 45 | BO | Blood Omen (game) |
| 46 | BO | Bloody Orchid (Lineage 2 game) |
| 47 | BO | Blow-Off |
| 48 | BO | Blue October (band) |
| 49 | BO | Boarding Officer |
| 50 | BO | Bochum (Germany) |
| 51 | BO | Body Odor |
| 52 | BO | Body Odour (gaming group) |
| 53 | BO | Boletim de Ocorrência (Accident Report; Brazil) |
| 54 | BO | Boletín Oficial (Spanish: Official Gazette; Argentina) |
| 55 | BO | Bolivia |
| 56 | BO | Bologna (Emilia Romagna, Italy) |
| 57 | BO | Bom Pra Otário (Brazil) |
| 58 | BO | Bonus Objective (gaming) |
| 59 | BO | Boom Operator (USAF in-flight refueling) |
| 60 | BO | Booster Orbiter |
| 61 | BO | Born Organized |
| 62 | BO | Borrow Output (electrical circuits) |
| 63 | BO | Bottom Opened (can collectors) |
| 64 | BO | Bourget-Opéra (French) |
| 65 | BO | Bowel Opening (anatomy) |
| 66 | BO | Bowled Over |
| 67 | BO | Box Office |
| 68 | BO | Brain Overload |
| 69 | BO | Branch Office |
| 70 | BO | Branch on Ones (IBM) |
| 71 | BO | Branch on Overflow (IBM) |
| 72 | BO | Branchiootic |
| 73 | BO | Break Off |
| 74 | B/O | Breakout |
| 75 | BO | Breakout Box |
| 76 | BO | Bridge Officer (gaming) |
| 77 | B/O | Broken Object |
| 78 | BO | Bronchiolitis Obliterans |
| 79 | BO | Bruto Oppervlakte (Dutch: Gross Area) |
| 80 | BO | Bucked Off (rodeo) |
| 81 | B/O | Budget Obligation |
| 82 | BO | Budget Obligations |
| 83 | BO | Budget Outlay |
| 84 | B/O | Budget Outlay |
| 85 | BO | Buffer Overflow/Overrun |
| 86 | BO | Build Order |
| 87 | BO | Bulletin Officiel (French) |
| 88 | BO | Burnout |
| 89 | BO | Bus Operator |
| 90 | BO | Business Object |
| 91 | BO | Business Office |
| 92 | BO | Business Opportunity |
| 93 | BO | Busy Out |
| 94 | BO | Buyer’s Option |
| 95 | B/O | Buyout (auctions) |
| 96 | BO | Buzz Off |