| S/NO | Abbr. | Meaning |
| 1 | BR | Babe Ruth (baseball player) |
| 2 | BR | Backbone Router |
| 3 | BR | Background Rhythm |
| 4 | BR | Backward Reporting |
| 5 | BR | Bacteriorhodopsin |
| 6 | BR | Bad Register |
| 7 | BR | Bad Religion (band) |
| 8 | BR | Bahama Route |
| 9 | BR | Bairro (Portuguese postal use) |
| 10 | BR | Baloch Regiment (Pakistan) |
| 11 | BR | Baltimore Ravens (professional football team; Maryland) |
| 12 | BR | Banana Republic (clothing store) |
| 13 | BR | Banco Reformador |
| 14 | BR | Bandwidth Request |
| 15 | BR | Bangladesh Railway |
| 16 | BR | Bank Roll |
| 17 | BR | Banlieue Rouge (Quebec punk band) |
| 18 | BR | Banque de la Réunion (French: Bank of Reunion) |
| 19 | BR | Bari (postal region, Somalia) |
| 20 | BR | Base Register |
| 21 | BR | Basic Research |
| 22 | BR | Baskin Robbins (ice cream stores) |
| 23 | BR | Batch Reactor (chemical reactor where volume is constant and the contents are well-mixed) |
| 24 | BR | Batch Record (pharmaceutical product recipe) |
| 25 | BR | Bathroom Reader |
| 26 | BR | Bâtiment Réacteur (French: Reactor Building) |
| 27 | BR | Batman Returns (1992 movie) |
| 28 | BR | Baton Rouge |
| 29 | BR | Bats Right (baseball) |
| 30 | BR | Battery Return |
| 31 | BR | Battle Realms (PC game) |
| 32 | BR | Battle Rezz (gaming) |
| 33 | BR | Battle Rifle (gaming, Halo) |
| 34 | BR | Battle Royale (Japanese movie) |
| 35 | BR | Bayerischer Rundfunk (Southern German Radio Station) |
| 36 | BR | Beam Rider (US DoD) |
| 37 | BR | Beam Rifle (anime, Mobile Suit Gundam) |
| 38 | BR | Bedrest |
| 39 | BR | Bedroom |
| 40 | BR | Bellevue Reporter (community newspaper) |
| 41 | BR | Bend Radius (cable flexibility) |
| 42 | B/R | Best Regards |
| 43 | BR | Best Regards |
| 44 | BR | Bharat Rakshak |
| 45 | BR | Bible Review |
| 46 | BR | Bidirectional Ring |
| 47 | BR | Bills Receivable |
| 48 | BR | Binary Restenosis |
| 49 | BR | Biological and Radiological |
| 50 | BR | Biological Research |
| 51 | BR | Biosphere Reserve (various locations) |
| 52 | BR | Birth Rate |
| 53 | BR | Bit Rate |
| 54 | bR | Bitte Rücksprache (German: Please Contact) |
| 55 | BR | Black Adder |
| 56 | BR | Black Reign (TNA iMPACT gaming wrestler) |
| 57 | BR | Blackburn Rovers |
| 58 | BR | Blackground Records (record label) |
| 59 | BR | Blade Rate |
| 60 | BR | Blade Runner (movie) |
| 61 | BR | Bloc Réacteur (French: Reactor Unit) |
| 62 | BR | Blockade Runner (game) |
| 63 | BR | Blonde Redhead (band) |
| 64 | BR | Blood Rayne (video game) |
| 65 | BR | Bloody Roar (video game) |
| 66 | BR | Blue Ridge |
| 67 | BR | Blue Rodeo (band) |
| 68 | BR | Blu-ray (Disc) |
| 69 | BR | Boca Raton (Florida) |
| 70 | BR | Bohemian Rhapsody |
| 71 | BR | Boilermaker (USN Rating) |
| 72 | BR | Bomber Reconnaissance |
| 73 | BR | Bombing Run (Unreal Tournament 2003 game mode) |
| 74 | BR | Bong Rip |
| 75 | BR | Book of Reference |
| 76 | BR | Bottle Rockets (band) |
| 77 | BR | Bottom Reflection |
| 78 | BR | Boundary Representation |
| 79 | BR | Boys Rule |
| 80 | BR | Branch |
| 81 | BR | Brandenberger+Ruosch AG |
| 82 | BR | Brasil/Brazil (top level domain) |
| 83 | BR | Brass |
| 84 | BR | Break (HTML) |
| 85 | BR | Break Rate |
| 86 | BR | Break Relay |
| 87 | BR | Breastroke (swimming) |
| 88 | BR | Breeder Reactor |
| 89 | B/R | Bridge/Router |
| 90 | BR | Bridgewire Resistance |
| 91 | BR | Bridleway (UK planning & zoning) |
| 92 | BR | Brigade de Recherche (French: Research Brigade) |
| 93 | BR | Brigate Rosse (Italian Terrorist Group) |
| 94 | BR | Brindisi, Puglia (Italian province) |
| 95 | BR | Britain |
| 96 | BR | British Rail |
| 97 | BR | British Railways (company) |
| 98 | BR | Broad Ripple (Indiana) |
| 99 | BR | Broker Reciprocity (real estate) |
| 100 | BR | Bromine |
| 101 | BR | Bromley (postcode, United Kingdom) |
| 102 | BR | Brother |
| 103 | BR | Brother Rat |
| 104 | BR | Brown |
| 105 | BR | Buddy Ride |
| 106 | BR | Budget Report |
| 107 | BR | Budget Review (US DoD) |
| 108 | BR | Buffalo Regals |
| 109 | BR | Buffer Register |
| 110 | BR | Build Report |
| 111 | BR | Builder’s Risk |
| 112 | BR | Bundesrat (Austrian Parlamentary Institution) |
| 113 | BR | Bureau of Reclamation |
| 114 | BR | Burlington Resources (energy company; Texas) |
| 115 | BR | Burst Rate (data communications) |
| 116 | BR | Business Reform |
| 117 | BR | Business Register |
| 118 | BR | Business Registration |
| 119 | BR | Business Release |
| 120 | BR | Business Result |
| 121 | BR | Business Roundtable |
| 122 | BR | Butadiene Resin |
| 123 | BR | Butadiene Rubber (polybutadiene rubber) |
| 124 | BR | Eva Airways Corporation (IATA airline code) |
| 125 | BR | Mist (Meteorological Report) |
| 126 | BR | Petrobrás Distribuidora (Brazil) |
| 127 | BR | Radiocommunication Bureau |