Companies catalogue
- O'Brien Timber Products Ltd, Ballinalsoe, Co. Galway
- O'Connor & Co, Cork
- O'Connor & Co, Cork
- O'Donnell Commercials, Buncrana
- O'Máille - The Original House of Style, Galway
- O'Neill and Flanagan -Auctioneers- Real-Estate-Agents-Valuers, Aughrim
- O'Neill,Thomas, Limerick
- OBW Technoligies, Birmingham
- OBW Technologies, Limerick
- Ocean Aesthetics, Letterkenny
- Ogam Aromatherapy, Co. Louth
- Olive's Seoul Food, Claremorris
- Olivia Naughton Counselling and Psychotherapy Dublin, Dublin
- OMS Auto Parts, Donegal
- OMS Auto Parts, Buncrana
- OMS Auto Parts - Ford Parts Cork, Cork
- One More Loans, Dublin 2
- One Step Clinic, Dublin 15
- Online Counselling Ireland, Waterford
- ORANGERIUM, Kilkelly
- Oriental Massage Galway, Galway
- Orthotic.ie by ReBalance Physiotherapy, Dublin
- Orthotic.ie by ReBalance Physiotherapy, Dublin
- OS Insulate, Schull
- OSA McQuilllan Accountant Dublin, Blackrock
- Osservi payroll services, Dublin 1
- Outooks, Longford
- Oven Sparkling Dublin, Portmarnock
- Owl Pest Control Ltd., Dublin
- Ozone Group | Cleaning Services, Dublin 12