| Union Presbyterian Church | Halton Hills |
| United Senior Citizens of Ontario, Burlington Club 9 - Mailing Address | Burlington |
| United Senior Citizens of Ontario | Toronto |
| University of Toronto, Oakville - School of Continuing Studies, University Lecture Series | Oakville |
| University of Toronto, Faculty of Dentistry, Dental Clinics | Toronto |
| Uptown Medical, Family Practice and Walk-in Clinic | Oakville |
| Uptown Medical Pharmacy, Pharmacy Services | Oakville |
| Urgent Care Pharmacy, Pharmacy Services | Acton |
| Urology Resource Centre | Burlington |
| Used Wheelchairs and Assistive Equipment - Where to Donate, Burlington | Burlington |
| Used Wheelchairs and Assistive Equipment - Where to Donate, Oakville | Oakville |
