| Organization Name(s) | Located In |
| Our Place Peel | Mississauga |
| Oak Park Moms and Tots | Oakville |
| Oakleaf Christian Junior School | Oakville (River Oaks) |
| Oakville Academy for the Arts (The), The Oakville Academy for the Arts Preschool, JK & SK Programs | Oakville (Iroquois Ridge) |
| Oakville Aquatic Club | Oakville |
| Oakville Aquatic Club, Sears I Can Swim Program | Oakville |
| Oakville Art Society | Oakville (Bronte) |
| Oakville Celtic Fiddle Club | Oakville |
| Oakville Childrens Choir (The) | Oakville |
| Oakville Christian School | Oakville |
| Oakville Cricket Club | Oakville |
| Oakville Crusaders Rugby Club | Oakville (Iroquois Ridge) |
| Oakville Curling Club | Oakville (Old Oakville) |
| Oakville Family Badminton Club | Oakville (Iroquois Ridge North) |
| Oakville Galleries, Art Classes and Camps | Oakville |
| Oakville Galleries, Elementary and Secondary School Programmes in English and French | Oakville |
| Oakville Girls Softball Association | Oakville |
| Oakville Gymnastics Club | Oakville (Glen Abbey) |
| Oakville Hornets Girls Hockey Association | Oakville |
| Oakville King's Community Badminton Club | Oakville (North of 5, East of Neyagawa) |
| Oakville Korean Church | Oakville (College Park) |
| Oakville Legion Track and Field | Oakville |
| Oakville Little League Baseball | Oakville |
| Oakville Minor Baseball Association | Oakville |
| Oakville Minor Lacrosse Association | Oakville |
| Oakville Museum At Erchless Estate, P A Days, School and March Break Programs, and Preschool Programs | Oakville |
| Oakville Museum At Erchless Estate, Summer Day Camp & Workshops | Oakville (Old Oakville) |
| Oakville Neighbourhood Watch Association | Oakville |
| Oakville Newcomers' Club | Oakville |
| Oakville Parent-Child Centre | Oakville (QEW West Corridor) |
| Oakville Parent-Child Centre, Daisy's Duds | Oakville |
| Oakville Parent-Child Centre, Discovery Station Nursery School, North Service Rd W | Oakville (QEW West Corridor) |
| Oakville Parent-Child Centre, Discovery Station Nursery School, Sixth Line | Oakville (River Oaks) |
| Oakville Parent-Child Centre, Just for Kids, Playtime/Building on Books | Oakville (QEW West Corridor) |
| Oakville Parent-Child Centre, Ontario Early Years Centre, Drop-in Programs | Oakville |
| Oakville Parent-Child Centre, Ontario Early Years Centre, North Service Road - Satellite location | Oakville |
| Oakville Parent-Child Centre, Ontario Early Years Centre, Parent and Tot Programs | Oakville |
| Oakville Parent-Child Centre, Ontario Early Years Centre, Parent Education and Information Service | Oakville |
| Oakville Parent-Child Centre, Ontario Early Years Centre, Sixth Line - Satellite location | Oakville (River Oaks) |
| Oakville Parent-Child Centre, Parent and Tot Programs | Oakville (QEW West Corridor) |
| Oakville Parent-Child Centre, Parenting Workshops | Oakville (QEW West Corridor) |
| Oakville Parent-Child Centre, Post-Partum Support Group | Oakville |
| Oakville Parent-Child Centre, Summer Session 2010 | Oakville |
| Oakville Parent-Child Centre, Toy Library | Oakville |
| Oakville. Parks and Open Space Department, Parks, Harbours and Forestry, Splash Pads | Oakville |
| Oakville. Parks and Open Space Department, Parks, Harbours, Forestry and Cemeteries, Outdoor Skating Rinks | Oakville |
| Oakville Public Library | Oakville (Old Oakville) |
| Oakville Public Library, Central Branch | Oakville (Old Oakville) |
| Oakville Public Library, Childrens Programs | Oakville (Old Oakville) |
| Oakville Public Library, Clearview Neighbourhood Branch | Oakville (Clearview) |
| Oakville Public Library, Glen Abbey Branch | Oakville (Glen Abbey) |
| Oakville Public Library, Iroquois Ridge Branch | Oakville (Iroquois Ridge) |
| Oakville Public Library, White Oaks Branch | Oakville (College Park) |
| Oakville Public Library, Woodside Branch | Oakville (Bronte) |
| Oakville Public Library, Woodside Branch, Special Needs | Oakville (Bronte) |
| Oakville. Recreation and Culture | Oakville |
| Oakville. Recreation and Culture, Facilities, Bronte Youth Centre | Oakville (Bronte - West of 3rd Line) |
| Oakville. Recreation and Culture, Facilities, Glen Abbey Recreation and Aquatic Centre | Oakville (Glen Abbey) |
| Oakville. Recreation and Culture, Facilities, Indoor and Outdoor Swimming Pools | Oakville |
| Oakville. Recreation and Culture, Facilities, Iroquois Ridge Community Centre | Oakville (Iroquois Ridge) |
| Oakville. Recreation and Culture, Facilities, Joshua's Creek Arenas | Oakville (QEW East Corridor) |
| Oakville. Recreation and Culture, Facilities, Kinoak Arena | Oakville |
| Oakville. Recreation and Culture, Facilities, Maple Grove Arena | Oakville |
| Oakville. Recreation and Culture, Facilities, Oakville Arena | Oakville |
| Oakville. Recreation and Culture, Facilities, Oakville Youth Centre | Oakville |
| Oakville. Recreation and Culture, Facilities, River Oaks Recreation Centre | Oakville (River Oaks) |
| Oakville. Recreation and Culture, Facilities, Skateboard Parks | Oakville |
| Oakville. Recreation and Culture Department, Adult Programs, Athletics, Fitness, Social Dance and Sports Programs | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Aquatic Leadership and Re-certification Courses | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Learn To Swim | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Learn to Swim, Adapted Aquatics for Children with Disabilities | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Private Swimming Lessons | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Specialty Programs | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Specialty Programs, Synchronized Swimming | Oakville |
| Oakville. Recreation and Culture Department, Aquatics, Waterfit | Oakville |
| Oakville. Recreation and Culture Department, Children and Youth, Dance Programs | Oakville |
| Oakville. Recreation and Culture Department, Children and Youth, Fitness; Pilates | Oakville |
| Oakville. Recreation and Culture Department, Children and Youth, Performing Arts: The Art of Acting | Oakville |
| Oakville. Recreation and Culture Department, Children and Youth, Specialty Programs | Oakville |
| Oakville. Recreation and Culture Department, Children and Youth, Sports Programs | Oakville |
| Oakville. Recreation and Culture Department, March Break Programs | Oakville |
| Oakville. Recreation and Culture Department, Preschool Programs, Fitness | Oakville |
| Oakville. Recreation and Culture Department, Preschool Programs, Tiny Tots Creative Times | Oakville |
| Oakville. Recreation and Culture Department, Recreational Skating | Oakville |
| Oakville. Recreation and Culture Department, Special Needs and Medical Conditions, Summer Camps, Teen Adventure Program | Oakville |
| Oakville. Recreation and Culture Department, Summer Camps, Art of Acting | Oakville |
| Oakville. Recreation and Culture Department, Summer Camps, Canoe Kids | Oakville (Old Oakville) |
| Oakville. Recreation and Culture Department, Summer Camps, Golf Camp Programs | Oakville |
| Oakville. Recreation and Culture Department, Summer Camps, Leader in Training Program | Oakville |
| Oakville. Recreation and Culture Department, Summer Camps, Summer Sizzlers | Oakville |
| Oakville. Recreation and Culture Department, Teen Programs, Art of Acting, Creative Times | Oakville |
| Oakville. Recreation and Culture Department, Teen Programs, Fitness/Pilates/Yoga | Oakville |
| Oakville. Recreation and Culture Department, Teen Programs, Learn to Lead | Oakville |
| Oakville. Recreation and Culture Department, Teen Programs, Oakville Youth Advisory Committee | Oakville |
| Oakville. Recreation and Culture Department, Teen Programs, Sports | Oakville |
| Oakville. Recreation and Culture Department, Youth, Creative Times, Art of Acting; Spook-Tacular | Oakville |
| Oakville. Recreation and Culture Department, Youth Centres, Youth in Active Recreational Development | Oakville |
| Oakville Scottish Country Dance Group | Oakville |
| Oakville Skating Club | Oakville (River Oaks) |
| Oakville Skating Club, Oakville EDGE Synchronized Skating Teams | Oakville (River Oaks) |
| Oakville Soccer Club Incorporated | Oakville |
| Oakville Speed Skating Club | Oakville (River Oaks) |
| Oakville Suzuki Association | Oakville |
| Oakville Suzuki Performing Arts Camp | Oakville |
| Oakville Swim Academy | Oakville |
| Oakville Vytis Basketball Association | Oakville |
| Oakville Yacht Squadron, Sailing School | Oakville (Old Oakville) |
| Oasis Centre des Femmes, FEMAIDE, Ligne de soutien pour femmes francophones victimes de violence | Toronto |
| Office of the Provincial Advocate for Children and Youth | Toronto |
| On Track Program | Halton Region |
| On Track Program, Employment Assistance Services | Halton Region |
| Ontario Community Newspapers Association, Ontario Junior Citizen of the Year Awards | Burlington |
| Ontario Federation of Teaching Parents | Ontario |
| Ontario. Ministry of the Attorney General, Family Justice Services Division, Office of the Children's Lawyer | Toronto |
| Ontario. Ministry of Children and Youth Services, Youth Justice Services, Halton Region Office | Burlington |
| Ontario. Ministry of Community and Social Services / Children and Youth Services, Special Needs, Assistance for Children with Severe Disabilities / Special Services At Home, Central West Region, Kitchener Office | Kitchener |
| Ontario. Ministry of Community and Social Services / Children and Youth Services, Special Needs, Assistance for Children with Severe Disabilities / Special Services At Home, Central West Region, Mississauga Office | Mississauga |
| Ontario. Ministry of Education, Trillium School | Milton |
| Ontario. Ministry of Health and Long-Term Care, Telehealth Ontario | Toronto |
| Ontario. Ministry of Training, Colleges and Universities, Employment Ontario Hotline | Toronto |
| Ontario. Ministry of Training, Colleges and Universities, Ontario Summer Jobs | Toronto |
| Ontario. Ministry of Training, Colleges and Universities, Student Support Branch, Ontario Student Assistance Program | Thunder Bay |
| Ontario. Ministry of Children and Youth Services / Ministry of Community and Social Services, Child and Family Services Review Board | Toronto |
| Operation Come Home | Ottawa |
| Options for Autism | Halton Region |
| Orchard Childrens Centre (The) | Burlington North |
| Our Community Cares Community Centre, Burloak Site | Burlington |
| Our Kids Network | Halton Region |
| Our Kids Network, Acton Hub | Acton |
| Our Kids Network, Aldershot Hub | Burlington |
| Our Kids Network, Milton Hub | Milton |
| Our Little World Childcare Centre | Oakville (Old Oakville) |
| Outdoor swimming areas | Ontario |
| Oxford Learning Centre, Burlington, Mountain Grove location | Burlington (Mountainside) |
| Oxford Learning Centre, Burlington, New Street Location | Burlington |
| Oxford Learning Centre, Oakville North | Oakville (Glen Abbey) |
| Oxford Learning Centre, Oakville North East | Oakville (North of Hwy 5) |
| Oxford Learning Centre, Oakville South | Oakville |