| Oakdale Child and Family Services, Oakdale Child and Family Service | Springwater |
| Oasis Centre des femmes | Toronto |
| OCASI - Ontario Council of Agencies Serving Immigrants, NewYouth.ca | Ontario |
| OCD North | Barrie |
| OCD Wellness | Barrie |
| Office of the Fire Marshal, Gravenhurst, Public Safety Training Division - Ontario Fire College Resource Centre | Gravenhurst |
| Ogemawahj Tribal Council, Ogemawahj Tribal Training and Economic Resources, Rama - 5984 Rama Rd | Chippewas of Rama First Nation |
| Ogemawahj Tribal Council, Rama - 5984 Rama Rd | Chippewas of Rama First Nation |
| Ombudsman for Banking Services and Investments, Toronto | Toronto Downtown |
| Ombudsman Ontario | Toronto |
| On My List Senior Assist, Mobile Service | Clearview (Simcoe County) |
| On Solid Ground, Autism & Behaviour Services | Barrie |
| Once Upon a Child | Barrie |
| One Church Barrie | Barrie |
| One Community, Free Thanksgiving Dinner | Collingwood |
| One Roof, Midland | Midland |
| Onstage Performance Group | Barrie |
| Ontario Aboriginal Housing Services | Sault Ste. Marie |
| Ontario Addiction Treatment Centres, Alliston Office | New Tecumseth |
| Ontario Addiction Treatment Centres, Collingwood Clinic | Collingwood |
| Ontario Association of Optometrists, Eye See...Eye Learn | Toronto Downtown Central |
| Ontario Camps Association | Toronto |
| Ontario Civilian Police Commission | Toronto |
| Ontario Clean Water Agency, Georgian Bay Highlands Plant | Springwater |
| Ontario College Application Service | Guelph |
| Ontario College of Trades | Toronto Downtown |
| Ontario Dental Association | Toronto Downtown North |
| Ontario Educational Leadership Centre | |
| Ontario Energy Board, Ontario Electricity Support Program (OESP) | Ontario |
| Ontario Energy Board | Toronto |
| Ontario Energy Board (Central East) | Toronto |
| Ontario Energy Board (Central East), Central East Ontario - No Physical Address, Low-Income Energy Assistance Program (LEAP) - Central East Application Sites | Toronto |
| Ontario English Catholic Teachers Association. Simcoe Muskoka Unit | Barrie |
| Ontario Federation for Cerebral Palsy | Etobicoke North |
| Ontario Federation of Snowmobile Clubs, Mailing Address | Barrie |
| Ontario Federation of Snowmobile Clubs, Simcoe County, Mid Ontario Snowmobile Trails | Tay |
| Ontario Federation of Teaching Parents | Ontario |
| Ontario Fencing Association | Toronto |
| Ontario Health - Trillium Gift of Life Network | Toronto Downtown Central |
| Ontario Health atHome, Barrie - Huronia Rd, Community Nursing Clinic | Barrie |
| Ontario Health atHome, Barrie - Lakeside Ter, Community Nursing Clinic | Barrie |
| Ontario Health atHome, Barrie - Sperling Dr, Children's Health Services | Barrie |
| Ontario Health atHome, Barrie - Sperling Dr, Health Care Connect | Barrie |
| Ontario Health atHome, Barrie - Sperling Dr, Mental Health and Addictions Nurses - School Program | Barrie |
| Ontario Health atHome, Barrie - Sperling Dr | Barrie |
| Ontario Health atHome, Barrie - Sperling Dr, Telehomecare | Barrie |
| Ontario Health atHome, Collingwood, Community Nursing Clinic | Collingwood |
| Ontario Health atHome, nsmhealthline.ca | Barrie |
| Ontario Health atHome, Muskoka Clinic, Community Nursing Clinic | Huntsville |
| Ontario Health atHome, Orillia Clinic, Community Nursing Clinic | Orillia |
| Ontario Hooking Craft Guild, Mailing Address | Minesing |
| Ontario Incontinence Supplies | New Tecumseth |
| Ontario Liberal Party, Barrie-Innisfil Provincial Electoral District Association | Barrie |
| Ontario Liberal Party, No Physical Address, Barrie-Springwater-Oro-Medonte Provincial Electoral District Association | Barrie |
| Ontario Medical Imaging, Midland | Midland |
| Ontario Medical Imaging, Ontario Breast Screening Program, Orillia | Orillia |
| Ontario Medical Imaging, Orillia, Memorial Avenue X-ray and Ultrasound | Orillia |
| Ontario Ministry of Natural Resources and Forestry, Ontario Hunter Education Program | Peterborough |
| Ontario Motor Vehicle Industry Council | Toronto |
| Ontario Nature | Toronto Downtown |
| Ontario Nurses' Association, Orillia, Regional Office | Orillia |
| Ontario Parents Advocating for Children with Cancer | Barrie |
| Ontario Parole Board, Victim Support | Toronto |
| Ontario Photo Card | Ontario |
| Ontario Poison Centre | Toronto Downtown Central |
| Ontario Provincial Police, Alliston, Nottawasaga Detachment | New Tecumseth |
| Ontario Provincial Police, Collingwood, Collingwood and The Blue Mountains Detachment, Collingwood | Collingwood |
| Ontario Provincial Police, Midland - Hwy 12, Southern Georgian Bay Detachment | Midland |
| Ontario Provincial Police, Midland - Second St, Southern Georgian Bay Detachment | Midland |
| Ontario Provincial Police, OPP Museum, Orillia - Memorial | Orillia |
| Ontario Provincial Police, OPP Satellite Office - Penetanguishene, Penetanguishene Satellite Office | Penetanguishene |
| Ontario Provincial Police, Orillia - Hurtubise Dr, Central Region Office | Orillia |
| Ontario Provincial Police, Orillia - Memorial, General Headquarters | Orillia |
| Ontario Provincial Police, Orillia - University Ave, Orillia Detachment, Orillia - University Ave | Orillia |
| Ontario Provincial Police, Project Safe Trade, Collingwood, Collingwood | Collingwood |
| Ontario Provincial Police, Wasaga Beach, Huronia West Detachment | Wasaga Beach |
| Ontario Registered Music Teachers Association, Barrie Branch, No Physical Address | Barrie |
| Ontario Senior Games Association | Barrie |
| Ontario Society for the Prevention of Cruelty to Animals, Orillia | Orillia |
| Ontario SPCA and Humane Society, Barrie - 91 Patterson Rd, Ontario SPCA - Barrie Animal Centre | Barrie |
| Ontario SPCA and Humane Society, Barrie - 91A Patterson Rd, Marion Vernon Memorial Animal Clinic | Barrie |
| Ontario SPCA Midland & District Animal Centre, Provincial Animal Transfer Hub, Community Support Services - Animal Centre and Adoption | Tay |
| Ontario Track3 Adaptive Sports Association, Toronto - Administrative Office | Toronto |
| Ontario Trails Council | Deseronto |
| Ontario Universities' Application Centre | Guelph |
| Ontario Vipassana Centre, Egbert, Dhamma Torana | Egbert |
| Ontario Water Centre (The) | Georgina |
| Ontario, Ministry of the Solicitor General, Barrie, Probation and Parole Services, Barrie | Barrie |
| Ontario, Ministry of the Solicitor General, Southwest Region - Midhurst, The Office of the Fire Marshal (OFM) | Springwater |
| Ontario. Members of Provincial Parliament, Barrie-Innisfil Riding, Provincial Constituency Office - Andrea Khanjin | Barrie |
| Ontario. Members of Provincial Parliament, Barrie-Springwater-Oro-Medonte Riding, Provincial Constituency Office - Doug Downey | Barrie |
| Ontario. Members of Provincial Parliament, Provincial Constituency Office - Brian Saunderson, Simcoe-Grey Riding - Stayner Office | Stayner |
| Ontario. Members of Provincial Parliament, Provincial Constituency Office - Brian Saunderson, Simcoe-Grey Riding - Stayner Office, Simcoe-Grey Riding - Stayner Office | Stayner |
| Ontario. Members of Provincial Parliament, Simcoe North Riding - Orillia Office, Provincial Constituency Office - Jill Dunlop, Simcoe North Riding | Orillia |
| Ontario. Members of Provincial Parliament, Simcoe-Grey Riding - Alliston Office, Provincial Constituency Office - Brian Saunderson, Simcoe-Grey Riding - Alliston Office | Alliston |
| Ontario. Members of Provincial Parliament, York-Simcoe Riding, Provincial Constituency Office - Caroline Mulroney | East Gwillimbury |
| Ontario. Ministry for Seniors and Accessibility | Toronto |
| Ontario. Ministry of Children, Community and Social Services | Barrie |
| Ontario. Ministry of Children, Community and Social Services, Barrie - 34 Simcoe St, Ontario Disability Support Program - Employment Support Program | Barrie |
| Ontario. Ministry of Children, Community and Social Services, Barrie - 34 Simcoe St, Ontario Disability Support Program | Barrie |
| Ontario. Ministry of Children, Community and Social Services, Barrie - Bayfield St, Youth Justice Division | Barrie |
| Ontario. Ministry of Children, Community and Social Services, Barrie - Ferris Lane, Passport Program | Barrie |
| Ontario. Ministry of Children, Community and Social Services, Collingwood, Youth Justice Division | Collingwood |
| Ontario. Ministry of Children, Community and Social Services, Huronia Regional Centre Record Information | Toronto |
| Ontario. Ministry of Children, Community and Social Services, Newmarket Office, Special Services at Home and Assistance for Children with Severe Disabilities | Newmarket |
| Ontario. Ministry of Children, Community and Social Services, Ontario Autism Program | Toronto |
| Ontario. Ministry of Children, Community and Social Services, Orillia, Youth Justice Division | Orillia |
| Ontario. Ministry of Children, Community and Social Services, Post Adoption Disclosure Unit | Toronto |
| Ontario. Ministry of Children, Community and Social Services. Family Responsibility Office | Toronto |
| Ontario. Ministry of Children, Community and Social Services. Support Services for Male Survivors of Sexual Abuse Program | Toronto |
| Ontario. Ministry of Children, Community and Social Services. Victim Support Line | Toronto |
| Ontario. Ministry of Community and Social Services, Employment and Training Start Up Benefit, Orillia | Orillia |
| Ontario. Ministry of Community and Social Services, Employment Supports, Orillia | Orillia |
| Ontario. Ministry of Community and Social Services, Accessibility for Ontarians with Disabilities Act, Online/Web Service | Ontario |
| Ontario. Ministry of Economic Development and Growth, Simcoe Muskoka Office | Springwater |
| Ontario. Ministry of Education, Central East Region, Child Care Quality Assurance and Licensing | Toronto |
| Ontario. Ministry of Environment, Conservation and Parks | Barrie |
| Ontario. Ministry of Environment, Conservation and Parks, Aurora District Office, Holland Marsh Provincial Wildlife Management Area | Bradford West Gwillimbury |
| Ontario. Ministry of Environment, Conservation and Parks, Awenda Provincial Park, Ontario Parks - Awenda Provincial Park | Penetanguishene |
| Ontario. Ministry of Environment, Conservation and Parks, Barrie Office | Barrie |
| Ontario. Ministry of Environment, Conservation and Parks, Copeland Forest, Midhurst (Huronia) District Office | Springwater |
| Ontario. Ministry of Environment, Conservation and Parks, Midhurst District Office, Midhurst (Huronia) District Office | Springwater |
| Ontario. Ministry of Environment, Conservation and Parks, Oro-Medonte, Ontario Parks - Bass Lake Provincial Park | Orillia |
| Ontario. Ministry of Environment, Conservation and Parks, Parry Sound District Office, Southern Region | Parry Sound |
| Ontario. Ministry of Environment, Conservation and Parks, Peterborough - Mailing Address, Natural Resources Information and Support Centre | Peterborough |
| Ontario. Ministry of Environment, Conservation and Parks, Port Severn, Ontario Parks - Six Mile Lake Provincial Park | Port Severn |
| Ontario. Ministry of Finance., Oshawa, Retail Sales Tax | Oshawa |
| Ontario. Ministry of Government and Consumer Services. Consumer Protection Ontario | Toronto |
| Ontario. Ministry of Health, Public Health Care | Toronto Downtown Central |
| Ontario. Ministry of Health, Trillium Drug Program | Etobicoke |
| Ontario. Ministry of Health, Health Care Connect | Toronto Downtown Central |
| Ontario. Ministry of Health, Health811 | Toronto Downtown Central |
| Ontario. Ministry of Health, Ontario's Fertility Program | Toronto Downtown Central |
| Ontario. Ministry of Health, Sexual Health Infoline Ontario | Toronto Downtown |
| Ontario. Ministry of Health, Smoking Cessation Program | Toronto Downtown Central |
| Ontario. Ministry of Health, Assistive Devices Program | North York Central |
| Ontario. Ministry of Health, Home Oxygen Therapy | North York Central |
| Ontario. Ministry of Health, Ontario Public Drug Programs | Etobicoke |
| Ontario. Ministry of Health, Ontario Health Insurance Plan | Toronto Downtown Central |
| Ontario. Ministry of Health, Dental Care For Low-Income Seniors | Toronto |
| Ontario. Ministry of Labour, Immigration, Training and Skills Development, Employment Ontario Contact Centre | Toronto |
| Ontario. Ministry of Labour, Immigration, Training and Skills Development [Central East], Barrie Regional Office, Apprenticeship Office, Barrie Regional Office | Barrie |
| Ontario. Ministry of Labour, Immigration, Training and Skills Development. Employment Practices Branch | Toronto |
| Ontario. Ministry of Labour, Immigration, Training and Skills Development. Employment Practices Branch, Newmarket, Ontario. Ministry of Labour, Immigration, Training and Skills Development. Employment Practices Branch, Central Region West, Newmarket | Newmarket |
| Ontario. Ministry of Long-Term Care, Long-Term Care Family Support and Action Line | Toronto Downtown Central |
| Ontario. Ministry of Long-Term Care, Reports on Long-Term Care Homes | Toronto Downtown Central |
| Ontario. Ministry of Municipal Affairs and Housing. Rental Housing Enforcement Unit | Toronto |
| Ontario. Ministry of Northern Development, Mines, Natural Resources and Forestry, Southern Region - Peterborough | Peterborough |
| Ontario. Ministry of Northern Development, Mines, Natural Resources and Forestry, Summer Jobs For Students and Internships, No physical address | Peterborough |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - 5th Floor, Crown Attorney | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - 5th Floor, Justice of the Peace - Criminal Matters | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - 5th Floor, Victim / Witness Assistance Program | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Office 301, Enforcement and Finance - Sheriff's Office | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Office 301, Estates Administration | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Office 301, Jury Line | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Office 301, Superior Court of Justice - Civil Filing Office | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Office 301, Superior Court of Justice - Family Court | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Office 301, Superior Court of Justice - Small Claims Court | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Room 303, Family Law Information Centre | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Room 313, Manager of Court Operations Office | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Room 412, Superior Court of Justice - Trial Coordinators Office | Barrie |
| Ontario. Ministry of the Attorney General, Barrie Courthouse - Room 501, Ontario Court of Justice - Criminal Court | Barrie |
| Ontario. Ministry of the Attorney General, Bracebridge Court House, Family Law Information Centre | Bracebridge |
| Ontario. Ministry of the Attorney General, Orillia Satellite Court, Ontario and Superior Court of Justice | Orillia |
| Ontario. Ministry of the Attorney General, Toronto, Office for Victims of Crime | Toronto Downtown |
| Ontario. Ministry of the Attorney General. Justice Ontario, Toronto | Toronto |
| Ontario. Ministry of the Attorney General. Office of the Children's Lawyer | Toronto |
| Ontario. Ministry of the Attorney General. Office of the Public Guardian and Trustee | Toronto |
| Ontario. Ministry of the Attorney General. Public Guardian and Trustee, Capacity Assessment Office | Toronto Downtown |
| Ontario. Ministry of the Environment, Conservation and Parks, Spills Action Centre | Toronto |
| Ontario. Ministry of the Solicitor General, Alliston Office, Probation and Parole Services, Alliston Office | New Tecumseth |
| Ontario. Ministry of the Solicitor General, Collingwood, Probation and Parole Services | Collingwood |
| Ontario. Ministry of the Solicitor General, Midland, Probation and Parole Services, Midland | Midland |
| Ontario. Ministry of the Solicitor General, Orillia, Probation and Parole Office, Orillia | Orillia |
| Ontario. Ministry of the Solicitor General, Penetanguishene, Central North Correctional Centre | Penetanguishene |
| Ontario. Ministry of Transportation, Barrie - Commerce Park Dr, Central Region - International Registration Plan | Barrie |
| Ontario. Ministry of Transportation, Barrie - No physical address, Senior Driver's Licence Renewal Program | Barrie |
| Ontario. Office of the Worker Adviser, Scarborough Office, Ontario. Office of the Worker Adviser, Scarborough Office | Toronto |
| Open Arms Early Childhood Centre, Barrie, Child Care Program | Barrie |
| Operation Christmas Child, Simcoe West | Barrie |
| Operation Ukrainian Safe Haven | |
| Operational Stress Injury Social Support Services, Central Ontario Region | Adjala-Tosorontio |
| OPP Youth Foundation, Youth Foundation, No physical address | Orillia |
| Optimist Club of Barrie, Optimist Beginner Golf League | Barrie |
| Order of The Eastern Star - Manson J. Bradley Chapter, #240, Chapter # 240 - Midland, Order of The Eastern Star | Midland |
| Orillia Aero Modelers | Gravenhurst |
| Orillia and Area Good Food Box, The | Orillia |
| Orillia and Area Physician Recruitment and Retention Committee | Orillia |
| Orillia and District Agricultural Society, Severn | Severn |
| Orillia and District Literacy Council, Literacy and Basic Skills, Orillia | Orillia |
| Orillia and District Literacy Council, Orillia | Orillia |
| Orillia and Lake Country Tourism | Orillia |
| Orillia Area Community Development Corporation, Peter St | Orillia |
| Orillia Badminton Club | Orillia |
| Orillia Ball Hockey Club, Orillia Ball Hockey League | Orillia |
| Orillia Central Preschool, Orchard Park Public School, Before and After School Care | Orillia |
| Orillia Central Preschool, Orchard Park Public School, Orchard Park - Infant, Toddler, Preschool and School Age Programs | Orillia |
| Orillia Central Preschool, St Bernard's Catholic Elementary School, Before and After School Care | Orillia |
| Orillia Central Preschool, St Bernard's Catholic Elementary School, Infant, Toddlers and Preschoolers Programs | Orillia |
| Orillia Community Gardens, Orillia - High St, High Street Park Community Garden | Orillia |
| Orillia Community Gardens, Orillia Public Library, Orillia Seed Library | Orillia |
| Orillia Community Nonprofit Housing Corporation | Orillia |
| Orillia Depression Anxiety and Manic Depression Self Help Group | Severn |
| Orillia Fairgrounds Farmers' Market | Orillia |
| Orillia Family Health Organization, Orillia, After Hours Clinic | Orillia |
| Orillia Fertility Associates | Orillia |
| Orillia Fine Arts Association | Orillia |
| Orillia First Aid | Orillia |
| Orillia Fish and Game Conservation Club | Orillia |
| Orillia Ladies Soccer League | Orillia |
| Orillia Law Association | Orillia |
| Orillia Lions Club | Orillia |
| Orillia Museum of Art and History (The) | Orillia |
| Orillia Native Women's Group | Orillia |
| Orillia Naturalists Club | Orillia |
| Orillia Pregnancy Resource Centre, Home With A Heart and Nurturing Fathers, Orillia | Orillia |
| Orillia Pregnancy Resource Centre, Orillia | Orillia |
| Orillia Public Library, General Services and Outreach, Orillia | Orillia |
| Orillia Public Library, Orillia, Coffee and Connect | Orillia |
| Orillia Public Library, Orillia, Family Department | Orillia |
| Orillia Public Library, Orillia, Onsite Human Service Coordinator | Orillia |
| Orillia Soldiers' Memorial Hospital, Barrie - EarlyON Child and Family Centre, After Baby Group | Barrie |
| Orillia Soldiers' Memorial Hospital, Bracebridge, After Baby Group | Bracebridge |
| Orillia Soldiers' Memorial Hospital, Children's Therapy Services, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Collingwood, After Baby Group | Collingwood |
| Orillia Soldiers' Memorial Hospital, Emergency Department, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Midland - EarlyON Child and Family Centre, After Baby Group | Midland |
| Orillia Soldiers' Memorial Hospital, North Simcoe Muskoka Regional Genetics Program, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Oncology and Blood Transfusion Adult Outpatient Clinic, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Ontario Breast Screening Program, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 170 Colborne St W - Cardiovascular Rehabilitation Program, Cardiovascular Rehabilitation Program | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 170 Colborne St W - Eleanor Johnson Wing, Community Mental Health Service | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 170 Colborne St W, Birthing Preparation Program | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 170 Colborne St W, Pediatric Diabetes Education Program | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 170 Colborne St W, Simcoe Regional Kidney Care Program | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 25 Museum Dr, Couchiching Health at Home | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 25 Museum Dr, Suite 175, Adult Diabetes Education Centre | Orillia |
| Orillia Soldiers' Memorial Hospital, Orillia - 80 Colborne St W - EarlyON Child and Family Centre, After Baby Group | Orillia |
| Orillia Soldiers' Memorial Hospital, Outpatient Physiotherapy, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Regional Domestic Violence Treatment Centre, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Regional Kidney Care Program Simcoe Muskoka at OSMH - Meals Made Easy, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Rehab Day Hospital, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Sexual Assault Treatment Centre, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Speech Language Pathology, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital, Volunteer Resources, Orillia - 170 Colborne St W | Orillia |
| Orillia Soldiers' Memorial Hospital Foundation | Orillia |
| Orillia Suns Volleyball Club | Orillia |
| Orillia Today | Orillia |
| Orillia Women Newcomers Club, Orillia Women's Newcomers Club | Orillia |
| Orillia X-Ray and Ultrasound | Orillia |
| Orillia Youth Centre | Orillia |
| Orillia, City of, Economic, Business Development and Communication Office, Orillia - Andrew St | Orillia |
| Orillia, City of, Orillia Wheelchair Limousine Service | Orillia |
| Orillia, City of, No physical address, Rest Stations for Extreme Weather Relief | Orillia |
| Orillia, City of, Orillia - 500 Gill St, Fire Department | Orillia |
| Orillia, City of, Orillia - Andrew St, Animal Control and Licensing | Orillia |
| Orillia, City of, Orillia - Andrew St, Environmental Services and Operations | Orillia |
| Orillia, City of, Orillia - Andrew St, Municipal Office | Orillia |
| Orillia, City of, Orillia - Andrew St, Recreation and Youth Services Division | Orillia |
| Orillia, City of, Orillia - Brammer Drive, Orillia Transit | Orillia |
| Orillia, City of, Orillia - Kitchener St, Environment and Infrastructure Services Department | Orillia |
| Orillia, City of, Senior Recreation, Seniors At Play Program | Orillia |
| Oro Agricultural Society | Oro-Medonte |
| Oro District Lions Club | Oro-Medonte |
| Oro Minor Hockey Association | Oro-Medonte |
| Oro Station Playschool | Oro-Medonte |
| Oro-Medonte Horticultural Society | Oro-Medonte |
| Oro-Medonte Minor Ball Association | Oro-Medonte |
| Oro-Medonte Minor Soccer | Oro-Medonte |
| Oro-Medonte Tennis Club | Oro-Medonte |
| Oro-Medonte Township, Hawkestone, Hawkestone Community Hall | Oro-Medonte |
| Oro-Medonte Township, Oro-Medonte - 1167 Old Barrie Rd W, Edgar Community Hall | Oro-Medonte |
| Oro-Medonte Township, Oro-Medonte - 396 Warminster Side Rd, Carley Community Hall | Oro-Medonte |
| Oro-Medonte Township, Oro-Medonte - 73 Eady Station Rd, Eady Community Hall | Severn |
| Oro-Medonte Township, Oro-Medonte - 837 Horseshoe Valley Rd E, Jarratt Community Hall | Oro-Medonte |
| Oro-Medonte Township, Oro-Medonte - Line 4, Arena & Community Banquet Hall | Oro-Medonte |
| Oro-Medonte Township, Oro-Medonte - Line 7 S, Municipal Office | Oro-Medonte |
| Oro-Medonte Township, Station #3 Headquarters (Coldwater), Fire & Emergency Services | Oro-Medonte |
| Orr Lake Ratepayers Association | |
| Oscar's Place Rehabilitation & Wellness Centre for Children | Collingwood |
| Osteoporosis Canada [Central East], Simcoe Muskoka - Mailing Address, Simcoe Muskoka Chapter | Clearview (Simcoe County) |
| Our Town Food Bank | Tottenham |
| Ovarian Cancer Canada | Toronto Downtown |
| Overall Independence, Mailing Address | Barrie |
| Overeaters Anonymous, Mailing Address, Central Ontario Intergroup | |
| Overeaters Anonymous, St Paul's Center Orillia OA Group, Living in Recovery | Orillia |
| Overeaters Anonymous, Wasaga Beach, Wasaga Beach Support Group | Wasaga Beach |
| Owen Hill Care Community, Barrie, Long Term Care Home | Barrie |
| Oxfam Canada | Ottawa |
| Oxford College, Bayfield Mall | Barrie |