| Bay Island Voyages | Boat tour agency | Mermaid Quay, lower board walk | Daily 11:30–18:30 |
| Be Kind Cleaning Services | Window cleaning service | The Tunnel Yard Alps, Quarry road | Mon–Fri 09:00–17:00 |
| Be Therapies | Aromatherapy service | 250 Cowbridge Rd E | Mon 09:00–18:00 |
| Beauty School Cardiff. | Beauty therapy college | Ste 5, 6-7 Bessemer Cl | Tue 10:00–19:00 |
| Belgravia Dermatology | Dermatologist | Cyncoed Consulting Room, Dartington Dr | Mon–Fri 09:00–17:00 |
| Bespoke Aura | Hair Replacement | Hair replacement service | Office 21, Willcox House, Dunleavy Dr | Mon 09:00–16:30 |
| Bettys Florists | Florist | 496 Cowbridge Rd E | Mon–Wed 09:00–17:00 |
| Birchgrove Dental Practice | Cosmetic dentist | 100 Caerphilly Rd | Mon–Thu 08:00–16:30 |
| Black Horse Limited | Car finance and loan company | St William House, Tresillian Terrace | Mon–Fri 09:00–17:00 |
| Blue Arrow Cardiff | Job centre | Ste 9, 4th Floor, Capital Tower, Business Centre, Greyfriars Rd | Mon–Fri 07:30–17:30 |
| Bmw & Mini Specialists @ A1-Diagnostics & Ecu Repairs | Repair service | 64 Sloper Rd | Mon–Fri 08:00–18:00 |
| Body & Soul Autoworks | Car restoration service | 28 Bessemer Rd | Mon 08:00–17:00 |
| Bolt Removals Ltd | Removals service | Clydesmuir Industrial Estate | Mon–Fri 08:00–18:00 |
| Booze 24/7 Alcohol Delivery Service | Beer shop | Wentloog Corporate Park | Daily Open 24 hours |
| British Heart Foundation | Charity shop | 45 Albany Rd | Mon–Sat 09:30–17:00 |
| British Soil Ltd | Topsoil supplier | Horticultural Works, Station Rd E | Mon–Fri 07:30–16:00 |
| Brooks Macdonald | Investment service | 3 Ty-Nant Ct | Mon–Fri 08:00–17:00 |
| Brown's Office Supplies (BOS Office) | Office supplies shop | Unit R2, Capital Business Park | Thu 08:30–17:00 |
| Bump Boobs Babi, Cardiff | Women's health clinic | Space2B: Room, The Maltings @, 300 E Tyndall St | Mon–Sat 09:30–16:30 |
| Bupa Dental Care Pentwyn | Dentist | Pentwyn Dr | Mon 08:00–20:00 |
| Bus4U Travel Minibus Hire | Transportation service | The Maltings, E Tyndall St | Daily Open 24 hours |
| By Mollie O'Brien | Make-up artist | 16 Fremington Pl | Daily 09:00–17:00 |
| C Smith Maintenance | Property maintenance | 80 Heol-Y-Coed | Mon 08:00–18:00 |
| Caesars Arms | Seafood restaurant | Heol Creigiau | Tue–Thu 12:00–14:30, 17:30–20:30 |
| Calvary Chapel Cardiff | Calvary chapel church | 5, Ash Tree Court, Gate International Business Park, Woodsy Cl | Wed 19:30–21:30 |
| Cambrian Plant Sales | Construction equipment supplier | Riverside Works Ely, Bridge | Mon–Fri 08:00–17:00 |
| Cancer Research UK | Charity shop | 16 Merthyr Rd | Mon–Sat 09:00–17:30 |
| CancerPal | Gift basket shop | 116 Station Rd | Daily Open 24 hours |
| Candy Jar Ltd | Video production service | 136 Newport Rd | Mon–Thu 09:00–17:00 |
| Cansford Laboratories - Drug and Alcohol Testing Services | Drug testing service | 1A, Pentwyn Business Centre, Wharfedale Rd | Tue 09:00–17:00 |