Services for O
- Oakwood Home Learning
- Oasis Health and Beauty Clinic
- Ocado Online Shopping
- Occupational Health - health, safety and well being in the workplace
- Occupational Therapy Service
- Octopus Community Network
- Odeon Cinema Holloway, Parent and Baby Screenings
- Off Beat - Beating Anxiety through Drumming
- Office Clearance UK - Office Furniture Clearance & Recycling Services
- Office of the Immigration Services Commissioner
- Old Street Post Office
- Olinka Greenhill
- One Housing Group
- One True Voice Women Organisation
- Online Baby Massage (IAIM) at Highbury Community Nursery
- Online Information
- Online Learning College
- Online Story and Rhyme Time
- Only Connect
- Opal Ward, Highgate Mental Health Centre
- OPAM (Organisation for HIV Positive African Men)
- Open access pan-disability football session for disabled young people
- Open Aikido Association
- Open Centre
- Open Mic Night at Christ Church Highbury
- Orama
- Organisation of HIV Positive African Men (OPAM)
- Origin Housing
- Oromo Community
- Ossian Guesthouse
- Osteopathic Centre for Children
- Otium Health and Leisure Club
- Our Lady and Saint Joseph's Church
- Our Space Advocacy Service, Elfrida Rathbone Camden
- Outlet
- The Outside Clinic - Home Visiting Opticians
- Outsiders Trust
- Oxygen Fitness Univers
- Oyewamiwa Temiloye Olubunmi