| IAVGO Community Legal Clinic | Toronto |
| Iglesia Pentecostal De Cristo Palabra Viva, Barrie | Barrie |
| Iglesia Pentecostal LaSenda, Barrie | Barrie |
| Imani's Place Foundation | New Tecumseth |
| Immaculate Conception Roman Catholic Church, Alliston | New Tecumseth |
| Inclusive Milestones Child Development Centres, Clinical Services | Barrie |
| Inclusive Milestones Child Development Centres, Educational Services | Barrie |
| Inclusive Milestones Child Development Centres, Recreation Services | Barrie |
| Income Security Advocacy Centre | Toronto |
| Independent Electricity System Operator, Mailing Address, Save on Energy | Barrie |
| Independent Living Services Simcoe County, Assisted Living Services | Barrie |
| Independent Living Services Simcoe County, Assistive Technology & Aging at Home | Barrie |
| Independent Living Services Simcoe County, Barrie, Homemaking Program | Barrie |
| Independent Living Services Simcoe County, Barrie | Barrie |
| Independent Living Services Simcoe County, Personal Support Services | Barrie |
| Independent Living Services Simcoe County, North Simcoe, Home Maintenance and Repair Service | Barrie |
| Indigenous Diabetes Health Circle, Central Region, Indigenous Diabetes Health Circle Central Region | Barrie |
| Information Orillia, Orillia Public Library, Accessible Advocacy Center | Orillia |
| Information Orillia, Orillia Public Library, Orillia Volunteer Centre | Orillia |
| Inner Growth Counselling & Psychotherapy | Barrie |
| Innisfil Community Church | Innisfil |
| Innisfil Community Church, Innisfil Food Bank | Innisfil |
| Innisfil Historical Society | Innisfil |
| Innisfil ideaLAB & Library, Cookstown Branch | Innisfil |
| Innisfil ideaLAB & Library, Lakeshore Branch | Innisfil |
| Innisfil ideaLAB & Library, Stroud Branch | Innisfil |
| Innisfil Taxi | Innisfil |
| Innisfil. Fire and Rescue Service | Innisfil |
| Inniswood Baptist Church | Barrie |
| Insurance Bureau of Canada, Consumer Information Centre | Toronto |
| Integrated Autism Consulting, Barrie | Barrie |
| Intelligent Elders Club (The) | Orillia |
| International Brotherhood of Electrical Workers, Barrie Office, Local 353 | Barrie |
| IOOF Seniors Homes, Barrie - 10 Brooks St, Odd Fellow and Rebekah Home | Barrie |
| IOOF Seniors Homes, Barrie - 20 Brooks St, Heritage Place | Barrie |
| IOOF Seniors Homes, Barrie - 90, 92, 94 Dean Ave, The Terraces at Heritage Square | Barrie |