Businesses
- B Cars Limited
- Bagots Hutton and Company Limited, wine, tea and general merchants
- Bailey Restaurant
- Bailey's Hotel
- Baird and Tatlock (London) Limited
- Baird's Limited, plumbing works and general contractors
- Baker Wardell and Company Limited
- Bakers' Union
- Ballinard Cooperative Agricultural and Dairy Society
- Ballsbridge Bakery
- Ballsbridge Show Grounds
- Ballywilliam Cooperative Society Limited
- Bank of Ireland
- Bankruptcy Office
- Bar Lock Typewriter Company Limited
- Barclay and Cook
- Barton O'Meara, solicitors
- Bass Ratcliff and Gretton Limited, brewers
- Baxendale and Company Limited
- Beauchamp and Orr, solicitors
- Becker Brothers, tea merchants
- Belfast Banking Company Limited
- Belvedere College
- Benrose and Sons
- Bernard Kiernan and Company Limited
- Bewley Sons and Company Limited
- Blackrock Hosiery Company Limited
- Blanchardstown Mills Limited
- Bloomsfield Laundry Company Limited
- Bluemel Brothers Limited
- Board of Trade
- Board of Works
- Bodega Company Limited
- Boileau and Boyd Limited, wholesale druggists
- Boland's Limited, millers and bakers
- Boutelleau and Company
- Bovril Limited
- Bow Lane Distillery
- Bow Street Distillery
- Boxwell and Brownrigg, solicitors
- Boy Messengers' Institute
- Boyd, Barrow and Company
- Boyers
- Boys' Home
- Brabant Creameries Limited
- Bray Head Hotel
- Bridge House
- British and Irish Steam Packet Company Limited
- British Automatic Company Limited
- British Expeditionary Force
- British Legal and United Provident Assurance Company Limited
- British Margarine Company Limited
- British Petroleum Company Limited
- British Stamp and Ticket Automatic Delivery Company
- Brooks Thomas and Company Limited
- Brown Thomas and Company Limited
- Browne and Gillmer Limited
- Burberry
- Burgess and Company
- Burgoyne Burbridges and Company Limited
- Burroughs Wellcome and Company
- Buswell's Hotel
- Butler's Medical Hall
- Buttle Brothers and Company, grocer
- Byrne Limited
- Byrne Mahony and Company