| Ian Anderson House | Oakville |
| IAVGO Community Legal Clinic | Toronto |
| iCARE Home Health Services | Oakville |
| ICNA Relief Canada, Head Office, Muslim Family Services - Food Bank | Mississauga |
| ICNA Sisters Milton, No Physical Address | Milton |
| IDA Brant Arts Pharmacy, Burlington - Brant St, Pharmacy Services | Burlington |
| IDA Brant Arts Pharmacy, Burlington - Brant St, Home Health Care Products | Burlington |
| IDA Burlington Drug Mart, Burlington - Guelph Line, Pharmacy Services | Burlington |
| IDA Burlington Heights Pharmacy, Burlington - Guelph Line, Pharmacy Services | Burlington |
| IDA Lotus Pharmacy, Burlington - Upper Middle Rd, Pharmacy Services | Burlington |
| IDA Maple Pharmacy, Burlington - Maple Ave, Pharmacy Services | Burlington |
| IDA MedProHealth Pharmacy, Burlington - Thomas Alton Blvd, Pharmacy Services | Burlington |
| IDA Mount Royal Pharmacy, Burlington - Mount Royal Plaza, Pharmacy Services | Burlington |
| IDA Pharmacy, Oakville - Grosvenor St (Medicare Pharmacy), Pharmacy Services | Oakville |
| IDA Pharmacy, Oakville - Kerr St, Pharmacy Services | Oakville |
| IDA Pharmacy, Oakville - Third Line (Royal Oak Pharmacy), Pharmacy Services | Oakville |
| IDA Pharmacy, Oakville - Argus Rd (St Mark's Pharmacy), Pharmacy Services | Oakville |
| IDA Pharmacy, Georgetown - Guelph St (King Cove Pharmacy), Pharmacy Services | Georgetown |
| IDA Pharmacy, Oakville - Queensbury Cres (Upper Middle Pharmacy), Pharmacy Services | Oakville |
| IDA Pharmacy, Oakville - Oak Park Blvd (Central Park Pharmacy), Pharmacy Services | Oakville |
| IDA Pharmacy, Oakville - Ford Dr (Ford Dr Pharmacy), Pharmacy Services | Oakville |
| IDA Pharmacy, Oakville (Sav-On Pharmacy), Pharmacy Services | Oakville |
| IDA St Mary Pharmacy, Burlington - Appleby Line, Pharmacy Services | Burlington |
| IDEA Burlington | Burlington |
| Ignite Artistic Swimming Club | Burlington |
| Immanuel Lutheran Church | Georgetown |
| Immigration and Refugee Board of Canada. Central Region | Toronto |
| Impactus | Promise Keepers Canada | Burlington |
| In Home Haircuts by Sam | Mississauga |
| Inclusion Canada | Toronto Downtown Central |
| Income Security Advocacy Centre | Toronto |
| Income Tax Clinics, Burlington | Burlington |
| Income Tax Clinics, Halton Hills | Halton Hills |
| Income Tax Clinics, Milton | Milton |
| Income Tax Clinics, Oakville | Oakville |
| INCommunities, 211 Central South Region Contact Centre | St Catharines |
| Independent and Free Press (The), Georgetown Market Place Mall | Georgetown |
| Independent Living Halton, Deborah's Home and Attendant Outreach Services | Milton |
| Independent Order of Oddfellows, Milton - Evening Star Rebekah Lodge 79 | Milton |
| Independent Order of Oddfellows, Oakville Lodges | Hamilton |
| Indigenous Diabetes Health Circle, Niagara Region, Indigenous Diabetes Health Circle, Niagara Region | Thorold |
| Indigenous Network | Mississauga |
| Indspire | Toronto |
| Indus Community Services, Oakville Office, Employment Services | Oakville |
| Indus Community Services, Brampton Gillingham Office, Family Services, Brampton Gillingham Office | Brampton |
| Indus Community Services, Newcomer Services, Brampton Gillingham Office, Brampton Gillingham Office | Brampton |
| Indus Community Services, Newcomer Services, Mississauga Head Office - Hurontario Suite 206, Mississauga Head Office - Hurontario Suite 206 | Mississauga |
| Infant Car Seats, Booster Seats, Halton | Halton Region |
| Infinity Health Centre, Oakville, Walk-in Clinic | Oakville |
| Information and Privacy Commissioner of Ontario | Toronto |
| Information Burlington, Burlington Public Library, Central Branch | Burlington |
| Information Halton Hills, Halton Hills Public Library | Halton Hills |
| Information Milton, Milton Public Library - Beaty Branch | Milton |
| Information Oakville, Oakville Central Library | Oakville |
| Injured Workers Community Legal Clinic | Toronto |
| Inkwell Montessori and GAE, Licensed Child Care Centre | Georgetown |
| Innocence Canada | Toronto |
| Innomar Specialty Pharmacy, Burlington - Harvester Rd, Pharmacy Services | Burlington |
| Inspire Halton | Halton Hills |
| Institute for Advancements in Mental Health, Burlington Support Group | Burlington |
| Institute for Advancements in Mental Health, Toronto Provincial Office | Toronto |
| Institute for Advancements in Mental Health (IAM), Oakville | Toronto |
| Insurance Bureau of Canada, Ontario Head Office, Consumer Information Centre | Toronto |
| Interfaith Council of Halton | Oakville |
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| International Association for Medical Assistance to Travellers | York Region |
| International Credential Assessment Service of Canada | Guelph |
| International Development and Relief Foundation, Toronto Office, Get Job Ready Youth Employment Program | Toronto |
| International Dyslexia Association - Ontario Branch, Tiny - Mailing Address | Tiny |
| International Railroad for Queer Refugees | Toronto |
| Interval House of Hamilton, Interval House of Hamilton Location, Interval House of Hamilton Services | Hamilton |
| In-Trend Home Solutions GTA | Etobicoke South |
| IODE, Oakville - Angela Bruce Chapter, Opportunity Shop | Oakville |
| Iranian Women's Organization of Ontario | Toronto |
| Ironwood Project (The) | Halton Hills |
| Iroquois Canoe and Outing Club | Halton Region |
| Iroquois Ridge Medical & Dermal, Family Practice and Walk-in Medical Clinic | Oakville |
| iScope Concussion and Pain Clinics, Mississauga | Cooksville |
| Islamic Community Centre of Milton | Milton |
| Islamic Relief Canada | Burlington |
| Italian Canadian Club of Burlington | Burlington |
| Italian Cultural Centre of Milton | Milton |
