Organization / Program Name(s)Located In
Oak Ridges Lions ClubOak Ridges
Oak Ridges Men's Recreational Hockey League, Oak Ridges Recreation Centre, Men's non-contact hockey leagueOak Ridges
Oak Ridges Moraine Land Trust, Cawthra Mulock Nature ReserveNewmarket
Oak Ridges Soccer ClubOak Ridges
Oak Ridges Trail AssociationKing City
Occupational Health Clinic for Ontario Workers (OHCOW)North York East
Occupational Health Clinic for Ontario Workers (OHCOW), Toronto, Occupational Health ClinicNorth York West
Occupational Health Clinic for Ontario Workers (OHCOW), Toronto, Inquiry and Information ServicesNorth York West
Occupational Health Clinic for Ontario Workers (OHCOW), Toronto, Medical Diagnostic ServicesNorth York West
Occupational Health Clinic for Ontario Workers (OHCOW), Toronto, Workplace AssessmentNorth York West
Ohr Somayach Subsidized Housing, Ohr Somayach Residential CentreThornhill East
Olive Branch Community Church (The)Markham
Olive Branch for Children, (The), Mailing AddressVaughan
Ontario Society of ChiropodistsNewmarket
One Kenton PlaceNorth York West
Ontario Addiction Treatment CentresNewmarket
Ontario Association of Residences Treating YouthMarkham
Ontario Association of Residents' CouncilsRichmond Hill
Ontario Association of Sign Language Interpreters, Professional Association of Sign Language InterpretersToronto Downtown
Ontario Autism CoalitionYork Region
Ontario Ball Hockey AssociationVaughan
Ontario Band AssociationMarkham
Ontario College of Traditional Chinese MedicineMarkham
Ontario EquestrianRichmond Hill
Ontario Genealogical Society, York Region BranchRichmond Hill
Ontario Hockey Federation, East Gwillimbury Sports Complex, East Gwillimbury Minor Hockey AssociationSharon
Ontario Junior Hockey League, Stouffville Spirit Junior A HockeyWhitchurch-Stouffville
Ontario Minor Hockey AssociationRichmond Hill
Ontario NatureToronto Downtown
Ontario Paralegal AssociationVaughan
Ontario Partnership on Aging and Developmental Disabilities, OAPDD Office - ReenaVaughan
Ontario Provincial Police.[York Region], Highway Safety Division HeadquartersAurora
Ontario Registered Music Teachers' AssociationYork Region
Ontario Secondary School Teachers' Federation, District 16 York RegionNewmarket
Ontario Shores Centre for Mental Health SciencesWhitby
Ontario SoccerVaughan
Ontario Society for the Prevention of Cruelty to Animals, Provincial Education and Animal Centre Provincial OfficeNewmarket
Ontario Society for the Prevention of Cruelty to Animals, Markham Cat Adoption and Education CentreMarkham
Ontario Society of Professional EngineersNorth York Central
Ontario Streams, Ontario Streams - Aurora Office, Environmental conservation and rehabilitationAurora
Ontario Table Tennis AssociationRichmond Hill
Ontario Taekwondo AssociationMarkham
Ontario Track 3 Ski Association for the DisabledEtobicoke South
Ontario Veterinary Medical Association, SafePetYork Region
Ontario Water Centre, (The), ClearWater FarmNewmarket
Ontario Wheelchair Sports AssociationToronto Downtown
Ontario Wound Care, The Judy Dan Research and Treatment CentreNorth York Central
Ontario York Region Heritage Lions ClubMarkham
Ontario. Members of Provincial Parliament.[York Region], Newmarket-Aurora Riding, Provincial Constituency Office - Christine ElliottNewmarket
Ontario. Members of Provincial Parliament.[York Region], Aurora-Oak Ridges-Richmond Hill Riding, Provincial Constituency Office - Michael ParsaRichmond Hill
Ontario. Members of Provincial Parliament.[York Region], King-Vaughan Riding, Provincial Constituency Office - Stephen LecceVaughan
Ontario. Members of Provincial Parliament.[York Region], Markham - Thornhill Riding, Provincial Constituency Office - Logan KanapathiMarkham
Ontario. Members of Provincial Parliament.[York Region], Markham-Stouffville Riding, Provincial Constituency Office - Paul CalandraWhitchurch-Stouffville
Ontario. Members of Provincial Parliament.[York Region], Markham-Unionville Riding, Provincial Constituency Office - Billy PangMarkham
Ontario. Members of Provincial Parliament.[York Region], Richmond Hill Riding, Provincial Constituency Office - Daisy WaiRichmond Hill
Ontario. Members of Provincial Parliament.[York Region], Thornhill Riding, Provincial Constituency Office - Gila MartowThornhill West
Ontario. Members of Provincial Parliament.[York Region], Vaughan - Woodbridge Riding, Provincial Constituency Office - Michael TibolloVaughan
Ontario. Members of Provincial Parliament.[York Region], York-Simcoe Riding, Provincial Constituency Office - Caroline MulroneyHolland Landing
Ontario. Ministry of Children, Community and Social Services, Newmarket - Central RegionNewmarket
Ontario. Ministry of Children, Community and Social Services, Newmarket - Central Region, Special Services At HomeNewmarket
Ontario. Ministry of Children, Community and Social Services, Newmarket - Tannery Mall, Youth Justice ServicesNewmarket
Ontario. Ministry of Children, Community and Social Services, Richmond Hill - Elgin Mills, Youth Justice ServicesRichmond Hill
Ontario. Ministry of Children, Community and Social Services. Ontario Disability Support Program[York Region], Newmarket - Central Region OfficeNewmarket
Ontario. Ministry of Community and Social Services, York Region Contact Centre, Ontario WorksRichmond Hill
Ontario. Ministry of Community and Social Services, Vaughan - Jane St, Ontario WorksVaughan
Ontario. Ministry of Community Safety and Correctional Services [York Region], Keswick Office - Simcoe Ave, Probation and ParoleKeswick
Ontario. Ministry of Government and Consumer Services. Consumer Protection OntarioToronto Downtown Central
Ontario. Ministry of Health, No physical address, Sexual Health Infoline Ontario/The MainlineToronto Downtown
Ontario. Ministry of Labour, Training and Skills Development[York Region], Markham Office, Apprenticeship OfficeMarkham
Ontario. Ministry of Labour. Employment Practices Branch [York Region], Central Region West, Newmarket, Ontario. Ministry of Labour. Employment Practices BranchNewmarket
Ontario. Ministry of Municipal Affairs and Housing. Disaster Recovery Assistance for OntariansToronto Downtown Central
Ontario. Ministry of Natural Resources [Aurora District]Aurora
Ontario. Ministry of the Attorney General [York Region], Newmarket CourthouseNewmarket
Ontario. Ministry of the Attorney General [York Region], Newmarket Courthouse, Victim/Witness Assistance ProgramNewmarket
Ontario. Ministry of the Attorney General, [York Region], Newmarket Courthouse, Newmarket Small Claims CourtNewmarket
Ontario. Ministry of the Solicitor General [York Region], Newmarket Office - Davis Drive, Probation and ParoleNewmarket
Ontario. Ministry of the Solicitor General [York Region], Richmond Hill Probation and Parole OfficeRichmond Hill
Ontario. Ministry of Transportation [York Region], Newmarket - Central Region Drivers and Vehicles - Yonge Street, Driver and Vehicle Licence Issuing OfficeNewmarket
Ontario. Ministry of Transportation [York Region], Newmarket - Central Region Drivers and Vehicles - Harry Walker Parkway, DriveTest Centre NewmarketNewmarket
Ontario. Ministry of Transportation [York Region], Sutton - Central Region Drivers and Vehicles - High Street, Driver and Vehicle Licence Issuing OfficeSutton
Ontario. Premier (Doug Ford)Toronto Downtown Central
Open Doorz ClubRichmond Hill
OpenMind Alliance AcademyRichmond Hill
Opera Bel CantoVaughan
Opera YorkThornhill East
Operation Springboard, Newmarket, Youth Court Action Planning ProgramNewmarket
Optimist Club of AuroraAurora
Optimist Club of KeswickKeswick
Optimist Club of Newmarket, Optimist Youth HallNewmarket
Or Hadash SynagogueNewmarket
Order of the Eastern Star - Newmarket Chapter #282Newmarket
OTN Telehomecare Program, Southlake Regional Health Centre, Central LHINNewmarket
Our Lady of SmolenskKeswick
Our Lady of the Lake Roman Catholic Church, Our Lady of the Lake Mission Roman Catholic Church, Catholic Place of WorshipKeswick
Our Lady Queen of the WorldRichmond Hill
Overeaters Anonymous - Central Ontario Intergroup.[York Region], Newmarket BranchNewmarket
Overeaters Anonymous - Central Ontario Intergroup.[York Region], Sutton BranchGeorgina