| Dance Ability Movement (The) | Milton |
| Dar Foundation | Oakville |
| Dar Foundation, Food Program | Oakville |
| Dare to be Youth Charity | Burlington |
| Darling Home for Kids | Milton |
| Deaf Muslims of Canada, Interpretation / Translation | Burlington |
| DeafBlind Ontario Services | Newmarket |
| DEBRA Canada | Oakville |
| Debtors Anonymous, Oakville - Mailing Address | Oakville |
| Developmental Services Ontario Central West Region, Single Point of Access for Adult Developmental Services | Milton |
| Diabetes Canada | Toronto Downtown Central |
| Diabetes Canada, D-Camps Ontario | Huntsville |
| Distress and Crisis Ontario | Waterloo |
| Distress Centre Halton | Halton Region |
| Distress Centres of Greater Toronto, Survivor Support Program | Toronto |
| Doctor's Office Urgent Care Clinic, Walk-in Medical Clinic | Burlington |
| Dolphins Swim Club | Oakville |
| Dream Kids Clinic and Pediatric Urgent Care | Oakville |
| Drury Lane Theatrical Productions | Burlington |
| Dundas Neyagawa Medical Centre, Family Practice and Walk-in | Oakville |
