Organization / Program Name(s)Located In
Oak Ridges FairOak Ridges
Oak Ridges Men's Recreational Hockey League, Oak Ridges Recreation Centre, Men's non-contact hockey leagueOak Ridges
Oak Ridges Moraine Land Trust, Newmarket - Cawthra Mulock Nature Reserve - Bathurst Street, ORM Land TrustNewmarket
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
OIP Coffee Catering, Mobile Catering Service, Employment Skills 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 Coalition, No Physical Address, Online Autism Advocacy groupYork Region
Ontario Ball Hockey Association, Ontario Ball Hockey Office, Ball hockey associationVaughan
Ontario Band Association, Mailing Address, Musical band association, honour bands and festivalsMarkham
Ontario College of Traditional Chinese Medicine, Main Campus Markham, Traditional Chinese Medicine collegeMarkham
Ontario Early Years Centre - Markham, Markham Ontario Early Years Centre Main Site, Early learning and literacy programsMarkham
Ontario Early Years Centre - Thornhill, Thornhill - Bayview Avenue, Early learning and literacy programsThornhill East
Ontario Energy Board, Central Hub, Ontario Electricity Support ProgramOntario
Ontario Equestrian Federation, Equestrian Federation Office, Equestrian competition and development programsRichmond Hill
Ontario Genealogical Society, York Region Branch, Richmond Hill Public Library, Promotes and fosters the study of genealogy and family historyRichmond 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 Marine Operators Association, Holland Landing BranchHolland Landing
Ontario Minor Hockey Association, OMHA Office, Hockey Clinics, Tournaments and programsRichmond Hill
Ontario NatureToronto Downtown
Ontario Paralegal AssociationVaughan
Ontario Partnership on Aging and Developmental Disabilities, OAPDD Office - Reena, Advocacy for Aging Adults with DisabilitiesVaughan
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 Office, 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 Disabled, Ontario Track 3 Ski Association for the Disabled - EtobicokeEtobicoke
Ontario Veterinary Medicine Association, SafePetYork Region
Ontario Water Centre, (The)Newmarket
Ontario Wheelchair Sports Association, Toronto - Sunrise Avenue, Promotes wheelchair sportsToronto Downtown
Ontario York Region Heritage Lions Club, Lions Club SEAS Centre, Community 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 Advanced Education and Skills Development, Markham Office, Apprenticeship OfficeMarkham
Ontario. Ministry of Children and Youth Services, Newmarket - Central RegionNewmarket
Ontario. Ministry of Children and Youth Services, Newmarket - Central Region, Special Services At HomeNewmarket
Ontario. Ministry of Children and Youth Services, Newmarket - Tannery Mall, Youth Justice ServicesNewmarket
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 and Social Services. Ontario Disability Support Program, Newmarket - Central Region OfficeNewmarket
Ontario. Ministry of Community and Social Services. Ontario Disability Support Program, Newmarket - Yonge Street, Ontario Disability Support ProgramNewmarket
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 Community Safety and Correctional Services, Toronto Anti-Guns and Gangs - Woodbine, Probation and Parole OfficeMarkham
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 - Eagle West, Newmarket CourthouseNewmarket
Ontario. Ministry of the Attorney General, Court Services, Newmarket - Eagle West, Newmarket Small Claims CourtNewmarket
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 North Service CounterAurora
Ontario. ServiceOntario, Aurora South Service CounterAurora
Ontario. ServiceOntario, Concord - Keele Street, Concord Service CounterConcord
Ontario. ServiceOntario, Keswick Service Counter, Ontario government services and informationKeswick
Ontario. ServiceOntario, Markham - Hwy 7, Markham Service CounterMarkham
Ontario. ServiceOntario, Newmarket - Yonge and Davis Centre, Newmarket Service CounterNewmarket
Ontario. ServiceOntario, Newmarket Service Counter - Yonge Street, Health Card ServicesNewmarket
Ontario. ServiceOntario, Richmond Hill - Yonge St, Richmond Hill Service CounterRichmond Hill
Ontario. ServiceOntario, Stouffville - Sandiford Drive, Stouffville Service CounterWhitchurch-Stouffville
Ontario. ServiceOntario, Thornhill - Steeles Ave, Thornhill Service CounterThornhill West
Ontario. ServiceOntario, Unionville - Hwy 7, Unionville Service CounterUnionville
Ontario. ServiceOntario, Woodbridge - Martin Grove Rd, Woodbridge Service CounterWoodbridge
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 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
Over 30 Baseball, Co-ed Baseball LeagueKeswick
Overeaters Anonymous - Central Ontario Intergroup, Newmarket - Taylor Funeral Home, Newmarket BranchNewmarket
Overeaters Anonymous - Central Ontario Intergroup, Sutton Youth Centre, Sutton BranchGeorgina