| Fabtronic - Event Production Northampton | Event management company | Unit 3, Summerhouse Rd | Mon–Fri 09:00–17:00 |
| Falcon Sales | Food products supplier | 7, Roe Farm, Whiston Rd | Mon–Fri 09:00–17:00 |
| Fast-Tech Supplies Ltd | Fastener supplier | Unit 34 Sywell Airport Business Pk | Mon–Fri 08:30–17:00 |
| Ferri Photography | Photographer | Manor Rd | Daily Open 24 hours |
| Fiat Motorvogue Northampton | Fiat dealer | 74 Kingsthorpe Rd | Mon 08:00–18:00 |
| Fibrelec Ltd | Fiber optic products supplier | 17 Ryehill Ct | Daily Open 24 hours |
| First Choice Cabling Ltd | Telecommunications contractor | 20A, 30 Abington St | Sat Open 24 hours |
| First Class Timber Ltd | Timber merchant | Little Bethel, Church St | Mon–Fri 08:00–17:00 |
| First Point Financial Management | Insurance agency | Talavera Court, Darnell Way | Mon–Fri 09:00–17:30 |
| Fitness Without Boundaries | Fitness centre | Crestwood Rd | Mon 10:00–14:00 |
| Fong Retreat (Formerly Fong Spa) | Day spa | The Stable, Clifford hill Mill Ln | Thu 10:00–18:00 |
| Fountain Construction Limited | Impresa di costruzioni | Sunnyways, 343 Billing Rd E | Mon–Fri 08:30–17:30 |
| Four Talent | Human resource consulting | Booth House, 1 Booth Ln N | Fri 09:00–17:30 |
| Fox & Hounds Lower Harlestone | Gastropub | Tillsist, 14 Harlestone Rd | Mon–Fri 11:00–23:00 |
| Freddy's Chicken & Pizzas | Chicken shop | 99 Weedon Rd | Mon–Thu 11:00–23:45 |
| Fusion Spice | Takeaway | 47 Bordeaux Cl | Mon 16:30–22:30 |
| Gabby Caswell MUA | Make-up artist | 4 Dairy Cl | Mon–Fri 09:00–19:00 |
| GAP Security | Car alarm supplier | K G House Kingsfield Way, 416 Kingsfield Way | Fri 09:00–18:00 |
| Garden Machines Northampton | Lawn mower shop | 66-70 Kingsthorpe Rd | Mon–Fri 08:30–17:30 |
| Gardner Webb Accounting | Bookkeeping service | Glebe House, 32 Webbs Ln, Overstone Rd | Mon 08:30–17:30 |
| Gastech | Gas company | 4 Mescalero | Mon–Sat 09:00–17:00 |
| GB Interiors Ltd | Construction company | Building 14 unit E3 The Depot | Mon–Fri 08:00–17:00 |
| Gem Celebrations Wedding and Event Hire | Event planning service | Unit 1, Sywell Aerodrome EGBK, Business Park, Wellingborough Rd | Thu 09:30–17:00 |
| GENR8 Energy Ltd | Solar panel maintenance service | 6 Staveley Way | Mon–Fri 09:00–17:00 |
| Ginza | Japanese restaurant | 156 Wellingborough Rd | Mon 13:00–22:00 |
| Glaze-Tech | Window supplier | Unit 1B, Industrial Estate, Kingsfield Cl | Mon 07:30–16:30 |
| Global Database | Business-to-business service | Artisans House, 7 Queensbridge | Mon–Thu 09:00–20:00 |
| Goldingtons Restoration | Masonry contractor | 59 Whitefield Rd | Daily 08:00–20:00 |
| Golfers Choice | Golf shop | Eagle Dr | Mon–Tue 09:30–17:00 |
| Goodyer Travel | Travel agent | 46 Main Rd | Mon–Fri 09:30–16:00 |