| Card Factory | Greetings card shop | 33 Commercial Rd, Totton Precinct | Mon–Sat 09:00–17:30 |
| Care & Mobility Centre Ltd | Mobility equipment supplier | 22 Shirley High St | Mon–Sat 09:00–16:30 |
| Caring Hands | Home care service | 4 Middle Rd | Daily 07:00–22:00 |
| Carolines T-Shirts | Screen printer | 484 Portswood Rd | Mon–Thu 09:00–17:00 |
| Carpet Cleaning Solutions Made Simple Ltd | Carpet cleaning service | 34 Northmore Rd | Mon–Fri 08:30–19:00 |
| Carters of Swanwick | Lawn mower shop | Duncan Rd | Mon 08:00–16:30 |
| Cartwright CS LTD | Customs broker | Arena Offices, Threefield House, GF25, Threefield Ln | Mon–Fri 09:00–17:00 |
| Catching Little Dreams | Sleep clinic | 36 Guildford Dr | Mon–Fri 09:00–17:00 |
| Catering and Hospitality - University of Southampton | Rental | University of Southampton Highfield Campus, 12 University Rd | Mon–Fri 09:00–17:00 |
| CEI Electrical Services Ltd | Electrical installation service | Unit 27, Solent Industrial Estate, Shamblehurst Ln S | Mon 07:00–17:00 |
| Century IT Services | IT support and services | Mill House Centre, 108 Commercial Rd | Thu 08:00–17:00 |
| Chamberlains Aqua and Energy Systems Limited (CAESL) | Energy equipment and solutions | Threefield House, Arena Business Centre, Threefield Ln | Mon–Fri 09:00–18:00 |
| Change Of Style Granite and Stone Ltd | Granite supplier | Unit 16, South Hampshire Industrial Park, Eddystone Road , Totton | Mon–Thu 08:00–17:00 |
| Chapman Glazing Solutions | Window installation service | 3 Ivy Court | Mon–Fri 07:30–16:30 |
| Charcoal Grill Totton | Kebab shop | 16 Rumbridge St | Daily 16:00–00:00 |
| Charms and Beads UK | Jewelry equipment supplier | Chevron Business Park | Mon–Fri 10:00–16:00 |
| Chartwell Green Surgery | Community health centre | 5 Wessex Rd | Mon–Fri 08:00–18:00 |
| Chefs and Events Staffing | Temp agency | Unit 3, Radcliffe Court, Radcliffe Rd | Mon 09:00–17:00 |
| Choose Health Physiotherapy & Acupuncture | Physical therapy clinic | 49 Portsmouth Rd | Mon–Fri 09:00–21:30 |
| Christopher Carter Vets | Veterinarian | 224 Winchester Rd | Mon–Fri 09:00–18:00 |
| circle.cloud | Telecommunications service provider | Ariadne House, Town Quay | Mon–Thu 07:00–17:30 |
| ClarisVision - Mr Aris Konstantopoulos | Eye care clinic | Hospital, Chalybeate Cl | Mon–Fri 09:00–17:00 |
| Clarke Lane Engineering | Sheet metal contractor | 101-121 Belgrave Rd | Mon 07:00–16:00 |
| Clean Contractors Ltd | Window cleaning service | Enterprise House, Ocean Way | Mon–Fri 08:00–17:00 |
| Clean2Gleam - Boat Cleaning - Hamble Point Marina | Cleaning service | Hamble Point Marina, School Ln | Daily 08:00–20:00 |
| Cleare HR Consulting Limited | Human resource consulting | 61 Freegrounds Rd | Mon–Fri 08:00–18:00 |
| Clem's Glazing Engineer and repairs | Engineer | South Western House, 418 Imperial Apartments | Daily Open 24 hours |
| CLF Distribution | Wholesaler | Units 3, Quest, 271 Test Ln | Mon–Fri 09:00–17:00 |
| Colin Charles Photography | Photography studio | The Studio, Botley Mills | Mon–Sat 10:00–17:00 |
| Commercial Fuel Solutions Limited | Industrial equipment supplier | H1, Adanac North, Adanac Dr | Mon–Fri 09:00–17:00 |