| Tay, Township of, Succursale Port McNicoll, Public Library, Port McNicoll Branch | Tay |
| Tay, Township of, Succursale Theo and Elaine Bernard, Victoria Harbour, Bibliothèque publique, Succursale Victoria Harbour | Tay |
| Tay, Township of, Succursale Waubaushene, Bibliothèque publique, Succursale de Waubaushene | Tay |
| Tay, Township of, Victoria Harbour - Tay Municipal Office, Services d'incendie | Tay |
| Tecumseth and West Gwillimbury Historical Society, association historique de Tecumseth et West Gwillimbury | Bradford West Gwillimbury |
| Teddy Bears Picnic Children's Centre | Clearview (Comté Simcoe) |
| Telecare Distress Line of Greater Simcoe, Orillia, Ligne de détresse Telecare du Grand Simcoe | Orillia |
| Temple de la renommée sportive de Penetanguishene | Penetanguishene |
| TestauVolant Serco DES Inc., Barrie, Centre d'examen du permis de conduire, Barrie | Barrie |
| Tetra Society of North America, Mailing Address, Section du Nord de l'Ontario | Oro-Medonte |
| The Guesthouse Shelter, Le Guesthouse et Carrefour communautaire | Midland |
| The Karma Project Community Food Co-operative, Coopérative alimentaire communautaire du projet Karma, Seed Youth Program | Port McNicoll |
| The Karma Project Community Food Co-operative, Jardin écologique, Penetanguishene | Penetanguishene |
| The Kinder Garden - Children's Centre for Excellence and Early Education | Essa |
| The Kinette Club of Wasaga Beach, Toys for Kids - Wasaga Beach | Wasaga Beach |
| The LearningHUB, Online/Web | Huron Nord |
| The Lighthouse Soup Kitchen and Shelter, Orillia, Orillia Christian Centre | |
| The Lighthouse Soup Kitchen and Shelter, Orillia, Refuge d'urgence pour hommes | Orillia |
| The Lighthouse Soup Kitchen and Shelter, Orillia, Services communautaires | |
| The Lighthouse Soup Kitchen and Shelter, Orillia, Supportive Housing | Orillia |
| The Sharing Place Food Bank, Orillia, Banque alimentaire The Sharing Place | Orillia |
| Theatre by the Bay, Labo de théâtre de Barrie | Barrie |
| Theatre by the Bay | Barrie |
| Third Age Barrie Lifelong Learning Assocation, Mailing Address, Association pour la formation continue du troisième âge de Barrie | Barrie |
| Three Links Cooperative Housing (Barrie), Logement coopératif Three Links (Barrie) | Barrie |
| Tiny (Canton de) | Tiny |
| Tiny (Canton de), Tiny - Bureau municipal, Municipal Office | Tiny |
| Tiny (Canton de), Wyevale, Services d'incendie et d'urgence | Tiny |
| Tiny-Shiny Childcare, Garderie Tiny-Shiny | Clearview (Comté Simcoe) |
| Tottenham Co-Op Preschool | New Tecumseth |
| Tottenham Medical Pharmacy | Tottenham |
| Tottenham Pharmasave | Tottenham |
| Touchstone Healing, Services de counselling et de psychothérapie holistiques | Collingwood |
| Towards Recovery Clinic, Barrie, clinique Towards Recovery, Barrie | Barrie |
| Tracks Employment and Resource Services of Georgian Bay | Collingwood |
| Tracks Employment and Resource Services of Georgian Bay, Collingwood, Services d'emploi de l'Ontario | Collingwood |
| Training for Life, Collingwood - No Physical Address | Collingwood |
| Tranquility Living Centre | Midland |
| TransUnion of Canada, Burlington | Burlington |
| Trauma and Life Stress Reduction, Réduction du stress de la vie et des traumatismes | Barrie |
| Treasured Kids School, École Treasured Kids | Oro-Medonte |
| Trent Hills. Bureau municipal, Caserne de Campbellford, Services d'incendie de Trent Hills | Trent Hills |
| Trent Hills. Bureau municipal, Caserne de Hastings, Services d'incendie de Trent Hills | Trent Hills |
| Trent Hills. Bureau municipal, Caserne Warkworth, Services d'incendie de Trent Hills | Trent Hills |
| Trent Lakes. Bureau municipal, Recherche et sauvetage | Trent Lakes |
| Tribunal de l'aide sociale | Toronto |
| Tribunal des droits de la personne de l'Ontario | Toronto |
| Trinity Anglican Church, Bradford, Église Anglicane Trinité | Bradford West Gwillimbury |
| Trinity United Church, Collingwood, Église unie Trinity | Collingwood |
| Trinity United Church, Collingwood, Food Pantry | Collingwood |
| Troubles de l'alimentation Anonyme, Service en ligne/Web | Barrie |
| Tuberous Sclerosis Canada Sclérose Tubéreuse | Barrie |
| TVO ILC | Toronto |