| Island Poké Brighton | Poke bar | 38 West St | Mon 11:30–20:30 |
| Isle of Avalon Ltd | Perfume store | 1 Hanningtons Ln | Thu 11:00–17:00 |
| Jackson Fire & Security (Brighton) | Fire protection service | Floor 5 & 6, Tower Point, 44 North Rd | Daily Open 24 hours |
| Jarzy's Appliance Repairs | Appliance repair service | 4 Parham Cl | Mon 09:00–19:00 |
| Jemma Jarman Permanent MakeUp | Permanent make-up clinic | 28, Temple House, 5 Fleet St | Sat 11:00–16:00 |
| Joie de Booth | Photography service | 32 Seaview Rd | Mon Open 24 hours |
| Jubilee Library | Public library | Jubilee Library, Jubilee St | Mon 10:00–17:00 |
| Julie Hall Hall: Celebrant | Marriage celebrant | 29 W Hill Rd | Thu 10:00–16:00 |
| Julien Plumart | Patisserie | 48 Queens Rd | Mon–Thu 08:00–17:30 |
| Kanatani toys | Toy shop | open market, Marshalls Row | Tue–Thu 11:00–17:00 |
| Kennedy Street Recovery Hub | Education centre | St Peter's Pl | Mon–Fri 10:00–17:00 |
| Kenshiro Gym | Martial arts club | Racecourse, Freshfield Rd | Mon–Fri 06:00–22:00 |
| Kicks Martial Arts Centre | Martial arts school | 185 Lewes Rd | Tue 16:30–20:30 |
| Kingdom People (Brighton) | Recruiter | 132 Queens Rd | Mon–Fri 08:30–17:30 |
| Kirk & Kirk | Optical wholesaler | The Knoll Business Centre, 325-327 Old Shoreham Rd | Tue 09:00–17:00 |
| Kitgum Kitchen | Eclectic restaurant | 3 Hampton Pl | Wed 18:00–23:00 |
| Lala Yusifova Gymnastics Academy | Gymnastics club | Village Way | Tue 17:00–19:00 |
| Lambert & Wade Rendering Specialists, Multi Award winning 2021-22-24 | Plasterer | 54 Swallows Rise | Mon–Fri 09:00–17:00 |
| Last Bookshop | Book shop | 40 Gardner St | Mon 10:00–18:00 |
| Lavash Gardner Street Brighton | Durum restaurant | 52 Gardner St | Sun 11:00–17:00 |
| Lavash North Street Brighton | Middle Eastern restaurant | 60 North St | Daily 11:00–22:00 |
| Lebanese Grill | Lebanese restaurant | 62 Queens Rd | Thu 05:00–01:00 |
| Level Skateboards | Skateboard shop | 35 Ditchling Rd | Mon 11:00–18:00 |
| Lewis & Co Planning | Consultant | 2 Port Hall Rd | Mon–Fri 09:00–17:30 |
| Life Size Architecture | Architectural designer | Ste 2, The Depot, 100 North Rd | Thu 09:00–18:00 |
| Linterns decorating | Painter and decorator | 14 Pankhurst Ave | Mon–Thu 08:00–20:00 |
| Local TV Aerials & Satellite Services | Antenna service | 19 Terminus Rd | Mon–Sat 08:00–18:00 |
| London & Brighton Plating | Metal finisher | 100 North St | Mon–Thu 08:00–17:00 |
| Lotus & Oak Limited | Chiropractor | 25c York Villas | Thu 08:00–19:00 |
| Louisa Martindale Building | Hospital | Eastern Rd | Mon 08:00–17:00 |