| Nar-Anon Family Groups of Ontario, Barrie | Barrie |
| Nar-Anon Family Groups of Ontario, Innisfil | Innisfil |
| Narcotics Anonymous, Central Lake Ontario Area | Oshawa |
| Narcotics Anonymous, Georgian Heartland Area | Clearview (Simcoe County) |
| National Association of Federal Retirees, Barrie, National Association of Federal Retirees - Huronia Branch 35 | Barrie |
| National Council of Jewish Women of Canada - Simcoe County, Mailing Address | Innisfil |
| National Eating Disorder Information Centre | Toronto Downtown Central |
| National Student Loans Service Centre | Mississauga |
| Naturally You Mastectomy and Bra Boutique, Barrie | Barrie |
| Nature Barrie | Barrie |
| Nature League, Collingwood - Mailing Address | Collingwood |
| Neuroclinic Barrie | Barrie |
| New Beginnings Support Group, Online/Web Service | Toronto |
| New Democratic Party of Canada, Barrie-Innisfil Federal Electoral District Association | Barrie |
| New Democratic Party of Canada, Barrie-Springwater-Oro-Medonte Federal Electoral District Association | Barrie |
| New Democratic Party of Ontario, No Physical Address, Barrie-Innisfil Provincial Electoral District Association | Barrie |
| New Democratic Party of Ontario, No Physical Address, Barrie-Springwater-Oro Medonte Provincial Electoral District Association | Barrie |
| New Farm Centre, Organic Food | Clearview (Simcoe County) |
| New Life Church, Collingwood | Collingwood |
| New Life Church, Collingwood, You in Mind Support Groups | Collingwood |
| New Life Clinic, Barrie, Virtual Methadone / Suboxone Addiction Clinic | Barrie |
| New Life Fellowship Baptist Church | Innisfil |
| New Path Youth and Family Services of Simcoe County, Alliston Office, Quick Access Counselling Clinic | New Tecumseth |
| New Path Youth and Family Services of Simcoe County, Alliston Office, Youth and Family Counselling Services | New Tecumseth |
| New Path Youth and Family Services of Simcoe County, Barrie - Lakeshore Dr, Attendance Centre | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie - Lakeshore Dr, Quick Access Counselling Clinic | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie - Lakeshore Dr, Youth and Family Counselling Services | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie Head Office, Adolescent Outreach Program | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie Head Office, Early Years Services | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie Head Office | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie Head Office, Parenting Support Programs | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie Head Office, Quick Access Counselling Clinic | Barrie |
| New Path Youth and Family Services of Simcoe County, Barrie Head Office, Youth and Family Counselling Services | Barrie |
| New Path Youth and Family Services of Simcoe County, Bradford Office, Quick Access Counselling Clinic | Bradford West Gwillimbury |
| New Path Youth and Family Services of Simcoe County, Bradford Office, Youth and Family Counselling Services | Bradford West Gwillimbury |
| New Path Youth and Family Services of Simcoe County, Collingwood Office, Quick Access Counselling Clinic | Collingwood |
| New Path Youth and Family Services of Simcoe County, Collingwood Office, Youth and Family Counselling Services | Collingwood |
| New Path Youth and Family Services of Simcoe County, Cookstown Office, Live in Treatment Services | Innisfil |
| New Path Youth and Family Services of Simcoe County, Midland Office, Quick Access Counselling Clinic | Midland |
| New Path Youth and Family Services of Simcoe County, Online / Web Service, Expand the Reach | Barrie |
| New Path Youth and Family Services of Simcoe County, Orillia Office, Quick Access Counselling Clinic | Orillia |
| New Path Youth and Family Services of Simcoe County, Orillia Office, Youth and Family Counselling Services | Orillia |
| New Tecumseth Public Library, Alliston, Memorial Branch | New Tecumseth |
| New Tecumseth Public Library, Beeton, DA Jones Branch | New Tecumseth |
| New Tecumseth Public Library, Tottenham, Pam Kirkpatrick Branch | New Tecumseth |
| New Tecumseth. Fire Department | New Tecumseth |
| New Tecumseth. Municipal Office | New Tecumseth |
| NEXIM Health Care Consultants, Barrie Office | Barrie |
| Next Gen Men | Simcoe |
| Next Gen Men, NGM Boys+ Club | Simcoe |
| NEXT STEP, Literacy and Basic Skills | New Tecumseth |
| NEXT STEP | New Tecumseth |
| Nigerian Community in Barrie - Canada, Barrie | Barrie |
| No Borders Fitness | Midland |
| Noor-Ul-Islam of Ontario, Barrie, Barrie Mosque | Barrie |
| North Simcoe Community Futures Development Corporation | Midland |
| North Simcoe Family Health Team (NSFHT), Diabetes Education Program, Prospect Blvd - Suite 3 | Midland |
| North Simcoe Family Health Team (NSFHT), Prospect Blvd - Suite 3, Same Day/Next Day Access Clinic | Midland |
| North Simcoe Muskoka Acquired Brain Injury Collaborative, Barrie | Barrie |
| North Simcoe Muskoka Hospice Palliative Care Network | Orillia |
| North Simcoe Muskoka Hospice Palliative Care Network, Orillia, Education and Palliative Pain and Symptom Management Consultations | Orillia |
| North Simcoe Muskoka Self Management Program, Wasaga Beach, Living a Healthy Life With Chronic Conditions or Chronic Pain | Wasaga Beach |
| North Simcoe Muskoka Self Management Program, Wasaga Beach, Powerful Tools for Caregivers | Wasaga Beach |
| North Simcoe Muskoka Specialized Geriatric Services, Barrie - Cundles Rd, Central Intake for Specialized Geriatric Services | Barrie |
| North Simcoe Ontario Health Team | Midland |
| North Simcoe Victim Services, Orillia, Victim Crisis Assistance Ontario | Orillia |
| North Simcoe Youth Wellness Hub, North Simcoe | Midland |
| North York General Hospital, Toronto - Phillips House, Child and Adolescent Eating Disorders Program | Toronto |
| Northern Air Quality Services | Barrie |
| Northern Home Foot Care, Mobile Services, Medical Foot Care Services | Muskoka District |
| Northern Stars Montessori School & Daycare, Barrie | Barrie |
| Northside Bible Chapel | Barrie |
| Nottawasaga Cooperative Homes | New Tecumseth |
| Nottawasaga Futures, Alliston, Business Excellence Resource Centre | New Tecumseth |
| Nottawasaga Valley Conservation Authority, Tiffin Centre for Conservation, Camp Tiffin | Utopia |
| Nottawasaga Valley Conservation Authority, Tiffin Centre for Conservation | Utopia |
| Nottawasaga Valley Conservation Authority, Tiffin Centre for Conservation | Utopia |
| Nottawasaga Valley Conservation Authority, Tiffin Centre for Conservation, Tiffin Nature School | Utopia |
| NSA Slo Pitch League (Barrie), Mailing Address, Indoor Winter Dome Slo-Pitch | Barrie |
| NSA Slo Pitch League (Barrie), Mailing Address, Outdoor Adult Summer Slo-Pitch | Midhurst |
| NT Power, Midland | Midland |