| Developmental Services Ontario, South West Region | London |
| Diabetes Canada | Toronto Downtown Central |
| Diabetes Canada, D-Camps Ontario | Huntsville |
| Dick's Barber Shop | Stratford |
| Dietitians of Canada | Toronto Downtown Central |
| Dietitians of Canada - UnlockFood.ca | Toronto Downtown Central |
| Discover Chiropractic | Stratford |
| Distance Education. Ontario Colleges of Applied Arts and Technology | Ontario |
| District 29 Senior Games, Burnside Agriplex | Stratford |
| Donegal Community Christian School | North Perth |
| dp Music Therapy | Central Huron |
| Drivetest, Stratford | Stratford |
| Drug Basics, Stratford | Stratford |
| Dublin & District Lions Club | West Perth |
| Ducks Unlimited Canada, Barrie | Barrie |
| Dying With Dignity Canada | Toronto |