| Jack Nathan Health, Alliston Walk-in Clinic, Alliston Walk-in Clinic at Walmart | New Tecumseth |
| Japanese Sword Society of Canada | Barrie |
| Jehovah's Witnesses. Barrie, Barrie - McKay Rd W, McKay Rd Kingdom Hall Congregations | Barrie |
| Jenkins (Dr Gwen) Clinical Psychologist | Barrie |
| Jennifer Ashleigh Children's Charity | Uxbridge |
| Jen's Place, Alliston, Residential Group Care Program | New Tecumseth |
| John Howard Society of Simcoe & Muskoka, Barrie - 80 Bradford St, Suite 228, Community Reintegration Services | Barrie |
| John Howard Society of Simcoe & Muskoka, Barrie - 80 Bradford St, Suite 228, Community Service Order Program - Adult | Barrie |
| John Howard Society of Simcoe & Muskoka, Barrie - 80 Bradford St, Suite 228, Digital Access to Justice Court Support Program | Barrie |
| John Howard Society of Simcoe & Muskoka, Barrie - 80 Bradford St, Suite 228, Institutional Services | Barrie |
| John Howard Society of Simcoe & Muskoka, Barrie - 80 Bradford St, Suite 228 | Barrie |
| John Howard Society of Simcoe & Muskoka, Barrie - 80 Bradford St, Suite 228, Record Suspension Assistance | Barrie |
| John Howard Society of Simcoe & Muskoka, Orillia - 17 Colborne St E | Orillia |
| John Howard Society of Simcoe & Muskoka, Orillia - 17 Colborne St E, Non-Residential Attendance Centre - North Simcoe | Orillia |
| Johnson Adult Foster Care | Vaughan |
| Johnson Children's Services | Vaughan |
| Journey to Diversity Workplaces, Barrie - Mailing Address | Barrie |
| Junior Achievement of Central Ontario | Toronto |
| Justice for Children and Youth | Toronto |
| Juvenile Diabetes Research Foundation Canada, Toronto | Toronto |