Organization / Program Name(s)Located In
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 Club, Club Office, Indoor and outdoor soccerOak Ridges
Oak Ridges Trail Association, King City - Head Office, Community Trails and Hiking AssociationKing City
Ohr Somayach Subsidized Housing, Ohr Somayach Residential CentreThornhill East
OIP Coffee Catering, Mobile Catering ServiceNewmarket
Olive Branch for Children, (The), Mailing AddressVaughan
Ontario Society of ChiropodistsNewmarket
One Parent Families Association of Canada, York Region ChapterRichmond Hill
One Parent Muslim FoundationMarkham
Ontario Addiction Treatment Centre, Ontario Addiction Treatment Centre NewmarketNewmarket
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 Association, Mailing Address, Musical band association, honour bands and festivalsMarkham
Ontario College of Traditional Chinese MedicineMarkham
Ontario Energy Board, Central Hub, Ontario Electricity Support ProgramOntario
Ontario Equestrian, Ontario Equestrian FederationRichmond Hill
Ontario Genealogical Society, York Region Branch, Richmond Hill Public LibraryRichmond Hill
Ontario Hockey Federation, East Gwillimbury Sports Complex, East Gwillimbury Minor Hockey AssociationSharon
Ontario Junior Hockey League, Whitchurch-Stouffville Recreation Complex, Stouffville Spirit Jr. A Hockey ClubWhitchurch-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, Aurora - Highway Safety Division Headquarters, Highway 407 DetachmentAurora
Ontario Registered Music Teachers' Association, Newmarket and Area Branch, Networking and professional development for registered music teachersYork Region
Ontario Secondary School Teachers' Federation, District 16 York RegionNewmarket
Ontario SoccerVaughan
Ontario Society for the Prevention of Cruelty to Animals, Provincial Education and Animal Centre Provincial Office, Animal Education and Adoption CentreNewmarket
Ontario Society for the Prevention of Cruelty to Animals, Markham Cat Adoption and Education CentreMarkham
Ontario Society of Professional Engineers, Mailing Address, PEO York ChapterYork Region
Ontario Streams, Ontario Streams - Aurora Office, Environmental conservation and rehabilitationAurora
Ontario Table Tennis AssociationRichmond Hill
Ontario Taekwondo AssociationMarkham
Ontario Tenants Rights, Online/Web ServiceYork Region
Ontario Tennis Association, In School Little Kids LeagueNorth York
Ontario Track 3 Ski Association for the DisabledEtobicoke
Ontario Veterinary Medical Association, SafePetYork Region
Ontario Water Centre, (The)Newmarket
Ontario Wheelchair Sports Association, Toronto - Sunrise Avenue, Promotes wheelchair sportsToronto Downtown
Ontario York Region Heritage Lions ClubMarkham
Ontario. Members of Provincial Parliament, Aurora-Oak Ridges-Richmond Hill Riding, Provincial Constituency Office - Michael ParsaYork Region
Ontario. Members of Provincial Parliament, King-Vaughan Riding, Provincial Constituency Office - Stephen LecceYork Region
Ontario. Members of Provincial Parliament, Markham - Thornhill Riding, Provincial Constituency Office - Logan KanapathiMarkham
Ontario. Members of Provincial Parliament, Markham-Stouffville Riding, Provincial Constituency Office - Paul CalandraYork Region
Ontario. Members of Provincial Parliament, Markham-Unionville Riding, Provincial Constituency Office - Billy PangMarkham
Ontario. Members of Provincial Parliament, Newmarket-Aurora Riding, Provincial Constituency Office - Christine ElliottYork Region
Ontario. Members of Provincial Parliament, Richmond Hill Riding, Provincial Constituency Office - Daisy WaiRichmond Hill
Ontario. Members of Provincial Parliament, Thornhill Riding, Provincial Constituency Office - Gila MartowThornhill West
Ontario. Members of Provincial Parliament, Vaughan - Woodbridge Riding, Provincial Constituency Office - Michael TibolloVaughan
Ontario. Members of Provincial Parliament, York-Simcoe Riding, Provincial Constituency Office - Caroline MulroneyYork Region
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. Ontario Disability Support Program, Newmarket - Central Region OfficeNewmarket
Ontario. Ministry of Children, Community and Social Services. Ontario Disability Support Program, Newmarket - Yonge Street, Ontario Disability Support ProgramNewmarket
Ontario. Ministry of Community and Social Services, York Region Contact Centre, Ontario WorksRichmond Hill
Ontario. Ministry of Community and Social Services, Newmarket - Central Region, Special Services at Home Advisory Committee (SSAH AC)Newmarket
Ontario. Ministry of Community and Social Services, Vaughan - Community Services and Housing, Ontario WorksVaughan
Ontario. Ministry of Community Safety and Correctional Services, Keswick Office - Simcoe Ave, Probation and ParoleKeswick
Ontario. Ministry of Community Safety and Correctional Services, Newmarket Office - Davis Drive, Probation and ParoleNewmarket
Ontario. Ministry of Community Safety and Correctional Services, Richmond Hill - 16th Avenue, Richmond Hill Probation and Parole OfficeRichmond Hill
Ontario. Ministry of Education. Ontario Early Years Centres, Richmond Hill - Bayview Avenue, YMCA of Greater Toronto Early learning and literacy programsRichmond Hill
Ontario. Ministry of Education. Ontario Early Years Centres, Vaughan-King-Aurora Ontario Early Years Centre, Early Years Parenting Centre and programsVaughan
Ontario. Ministry of Labour. Employment Practices Branch, Central Region West, NewmarketNewmarket
Ontario. Ministry of the Attorney General, Newmarket Courthouse, Victim/Witness Assistance ProgramNewmarket
Ontario. Ministry of the Attorney General, Court Services, Newmarket CourthouseNewmarket
Ontario. Ministry of the Attorney General, Court Services, Newmarket Courthouse, Newmarket Small Claims CourtNewmarket
Ontario. Ministry of Training Colleges and Universities, Markham Office, Apprenticeship OfficeMarkham
Ontario. Ministry of Transportation, Newmarket - Central Region Drivers and Vehicles - Harry Walker Parkway, DriveTest Centre NewmarketNewmarket
Ontario. Ministry of Transportation, Newmarket - Central Region Drivers and Vehicles - Yonge Street, Driver and Vehicle Licence Issuing OfficeNewmarket
Ontario. Ministry of Transportation, Sutton - Central Region Drivers and Vehicles - High Street, Driver and Vehicle Licence Issuing OfficeSutton
Ontario. ServiceOntario, Aurora - Bloomington Rd Service CounterAurora
Ontario. ServiceOntario, Aurora - Wellington St Service CounterAurora
Ontario. ServiceOntario, Concord - Keele St Service CounterVaughan
Ontario. ServiceOntario, Keswick - Church St Service CounterKeswick
Ontario. ServiceOntario, Markham - Hwy 7 Service CounterMarkham
Ontario. ServiceOntario, Newmarket - Yonge St Service CounterNewmarket
Ontario. ServiceOntario, Richmond Hill - Yonge St Service CounterRichmond Hill
Ontario. ServiceOntario, Stouffville - Sandiford Dr Service CounterWhitchurch-Stouffville
Ontario. ServiceOntario, Thornhill - Steeles Ave Service CounterThornhill West
Ontario. ServiceOntario, Unionville - Highway 7 Service CounterMarkham
Ontario. ServiceOntario, Woodbridge - Martin Grove Rd Service CounterVaughan
Open Doorz ClubRichmond Hill
OpenMind Alliance AcademyRichmond Hill
Opera Bel Canto, Rehearsals at Fontana Gardens, Community Opera CompanyVaughan
Opera York, Professional opera performances, education and outreachThornhill East
Operation Come Home, Ottawa - Gloucester Street, Assists at-risk and homeless youthOttawa
Operation Springboard, Newmarket Youth Justice CommitteeNewmarket
Optimist Club of Aurora Incorporated, Optimist Club Aurora, Service ClubAurora
Optimist Club of KeswickKeswick
Optimist Club of Newmarket, Newmarket - Optimist Youth Hall, Community Service ClubNewmarket
Or Hadash Synagogue, Or Hadash Synagogue - Newmarket, Place of worship and Community CentreNewmarket
Order of the Eastern Star - Newmarket Chapter #282, Newmarket - Masonic Hall - Millard Avenue, Mason ClubNewmarket
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 World, Our Lady Queen of the World Parish - Richmond Hill, Place of worshipRichmond Hill
Overeaters Anonymous - Central Ontario Intergroup, Newmarket - Taylor Funeral Home, Newmarket BranchNewmarket
Overeaters Anonymous - Central Ontario Intergroup, Sutton Youth Centre, Sutton BranchGeorgina