| Ontario Society for Chinese Education | Brampton | $15K |
| Ontario Society for Crippled Children | Toronto | $10.6M |
| Ontario Society for the Prevention of Cruelty to Animals | Stouffville | $29.6M |
| Ontario Society of Senior Citizens Organizations/la Societe d'Organisations des Citoyens Aines de l'Ontario | Toronto | $430K |
| Ontario Sports Hall of Fame | Toronto | $210K |
| Ontario Standardbred Adoption Society | Moffat | $305K |
| Ontario Steam Foundation | North York | — |
| Ontario Steam Heritage Museum | Puslinch | $163K |
| Ontario Streams | Aurora | $1.1M |
| Ontario Street Baptist Church | Stratford | $58K |
| Ontario Student Awards Foundation | Toronto | — |
| Ontario Student Debating Union | Toronto | $34K |
| Ontario Thinking Forward Leadership Centre | Toronto | — |
| Ontario Track3 Adaptive Sports Association | Etobicoke | $623K |
| Ontario Trails Council Inc. | Deseronto | $29K |
| Ontario Vipassana Foundation | Egbert | $1.1M |
| Ontario Visually Impaired Golfers Corporation | Sunderland | $57K |
| Ontario Vocal Festival | Etobicoke | $26K |
| Ontario Volunteer Emergency Response Team (overt) Inc | Bowmanville | $16K |
| Ontario Wapiti Restoration Association | Madoc | — |
| Ontario Weimaraner Rescue and Assistance (OWRASSIST) | ST Catharines | $21K |
| Ontario Wilderness Lodge | Hamilton | -$139K |
| Ontario Wildlife Foundation | Peterborough | $149K |
| Ontario Wildlife Rescue Centre | Etobicoke | $39K |
| Ontario Women's History Network/le Reseau d'Histoire des Femmes | Stittsville | $10K |
| Ontario Woodcarvers Association | Alma | $7,622 |
| Ontario Wound CARE | Toronto | $786K |
| Ontario Youth Parliament Association Inc. | Ottawa | $27K |
| Ontario Zoroastrian Community Foundation | Oakville | $1.3M |
| Ontariogreen Conservation Association | Jordan Station | $22K |
| Ontrack Institute of Christian Leadership (canada) | Richmond | — |
| Onward Gospel Church | Verdun | $308K |
| Onward Homes Society | Calgary | $21.1M |
| Ooknakane Friendship Centre | Penticton | — |
| Oorah Charitable Organization Oeuvre de Bienfaisance Oorah | Toronto | $11.6M |
| Ootsa Lake Bible Camp Society | Burns Lake | $97K |
| Opal III - Fredericton Respite Services Inc. | Fredericton | $423K |
| Opal Inc. | Sussex | $1.2M |
| Opaskwayak Educational Authority Inc. | Opaskwayak | $29.5M |
| OPCM (Orchestre Philharmonique et Choeur des Mélomanes) | Montreal | $725K |
| Open Air Campaigners Incorporated | Wingham | $652K |
| Open Arms | Tillsonburg | $47K |
| Open Arms Bible Fellowship Inc. | Nipawin | $17K |
| Open Arms Children's Foundation | Toronto | — |
| Open Arms Church of Jesus Christ | Pickering | $277K |
| Open Arms Church Parrsboro | Parrsboro | $138K |
| Open Arms Community Church of God | Windsor | $130K |
| Open Arms Early Childhood Centre Barrie | Barrie | $1.5M |
| Open Arms Equipping Ministries Inc. | Yarmouth | $9,631 |
| Open Arms Mission of Welland Inc. | Welland | $4.7M |
| Open Arms Resource Centre Society | Kentville | $1.8M |
| Open Arms Seventh Day Baptist Church | Markham | $120K |
| Open Bible Baptist Church | Missisauga | $7,645 |
| Open Bible Baptist Church (aylmer) | Aylmer | $125K |
| Open Bible Chapel Foundation | Vancouver | $916K |
| Open Door Apostolic Church Inc | Hamilton | $2,325 |
| Open Door Baptist Church Corp. | Saskatoon | $72K |
| Open Door Christian Fellowship | London | $471K |
| Open Door Church of Jesus-Christ | Laval | $33K |
| Open Door Community Ministries | Richmond | $42K |
| Open Door Fellowship of Elizabethtown-Kitley | Brockville | $224K |
| Open Door Foursquare Church | Port Coquitlam | $0 |
| Open Door Healing Center Pentecostal Church Of God Inc. | North York | $21K |
| Open Door Healing Rooms Society | Powell River | $32K |
| Open Door Ministries Inc. | Carbonear | $88K |
| Open Door Ministries Inc. | Charlottetown | $124K |
| Open Door Ministries Inc. | Morris | $130K |
| Open Door Pentecostal Church of Jesus Christ Apostolic | Mississauga | $28K |
| Open Door Senior Fellowship of Calgary | Calgary | — |
| Open Door Social Services Society | Vancouver | $28.7M |
| Open Door Womens CARE Centre | Halifax | $177K |
| Open Doors Canada | Halton Hills | $4.1M |
| Open Doors Mental Health for Children Youth & Families | Smiths Falls | $3.9M |
| Open Doorways Orphanage Inc. | Beausejour | $42K |
| Open Ears Festival of Music and Sound | Kitchener | $96K |
| Open for Life Ministries Canada | Pickering | $69K |
| Open Hands Global Relief and Health Programs | Oakville | $88K |
| Open Hands Ministry Inc. | Dugald | — |
| Open Heart Ministries | Mount Elgin | — |
| Open Heaven Intercessory & Praise Ministry | London | $7,825 |
| Open Heaven Ministries Inc | Toronto | $53K |
| Open Heavens Church | Airdrie | $4,524 |
| Open House | Vineland | — |
| Open Ice For Kids Inc. | Moncton | $4,758 |
| Open in Spirit to God Covenant Community St. Francis Xavier Mississauga | Mississauga | $61K |
| Open Medicine Foundation Canada | Victoria | $1.9M |
| Open Mind Education Foundation | Richmond | $6,220 |
| Open Road Chapels | Severn | $247K |
| Open Sky | Calgary | $644K |
| Open Sky Co-operative Ltd. | Sackville | $722K |
| Open Sky International Centre | Richmond Hill | $17K |
| Open Space Arts Society | Victoria | $512K |
| Open Studio | Toronto | $816K |
| Open to Grow | Calgary | $85K |
| Open Valley Cowboy Church | Armstrong | $26K |
| Open Voices Community Choir | Kingston | $52K |
| Open Way Community Church | Vancouver | $111K |
| Open Word Ministries | Niagara Falls | $7,040 |
| Opendoor Filipino Church of Calgary | Calgary | $40K |
| Opening Gaits Therapeutic Riding Society of Calgary | Calgary | $76K |
| Opening Hearts | Hamilton | — |
| Opening Nite Theatre Society | Mission | $39K |
| Openroad Foundation | Richmond | $727K |
| Opeongo Seniors Centre | Barry's Bay | $132K |
| Opeq (ordinateurs pour Ecoles du Quebec) | Montréal | $9.3M |
| Opera Belcanto of York | Bradford | $300 |
| Opéra bouffe du Québec | Laval | $172K |
| Opera Canada Publications | East York | $309K |
| Opéra de Montréal | Montreal | $12.4M |
| Opéra de Québec inc. | Quebec | $2.4M |
| Opéra du Royaume | Chicoutimi | $258K |
| Opera Five Inc. | Toronto | $107K |
| Opera in Concert | Toronto | $171K |
| Opera Kelowna Society | Kelowna | $381K |
| Opera Nova Scotia Society | Halifax | $41K |
| Opera Nuova-Newly United Operatic Vocalists Association | Edmonton | $714K |
| Opera on the Avalon Inc. | ST. John's | $1M |
| Opera-Theatre de Rimouski Inc. | Rimouski | $15K |
| Opéra/Théatre Voxpopuli | Montréal | $257K |
| Opera West Society | Vancouver | $266K |
| Opera York | Thornhill | $301K |
| Operation Amigo Building Society | Sylvan Lake | $20K |
| Operation Catch-Up | North York | $6,500 |
| Operation Christman Tree | Corunna | $78K |
| Operation Christmas Tree Inc. | Markham | — |
| Operation Come Home | Ottawa | $2.9M |
| Operation Come Home Foundation | Ottawa | — |
| Opération Compagnons d'armes | Quebec | $1,300 |
| Operation Dawn Canada | Scarborough | $191K |
| Operation Enfant Soleil | Quebec | $28.9M |
| Operation Exodus Canada | Milton | — |
| Operation Eyesight Canada | Calgary | $9.2M |
| Operation Feed Saint John Inc. | Rothesay | $198K |
| Operation Freedom Paws Canada Society | Fanny Bay | $255K |
| Operation Friendship Seniors Society | Edmonton | $6.8M |
| Operation Harvest Sharing | Brockville | $711K |
| Operation Jeunesse Ville-Emard/cote ST-Paul | Montreal | $273K |
| Operation Kickstart Society of Alberta | Calgary | $251K |
| Operation Mobilization Canada | Port Colborne | $8.6M |
| Opération Placement Jeunesse Inc. | Montreal | $271K |
| Operation Rainbow Canada | Vancouver | $88K |
| Operation Santa Clause | Laval | — |
| Operation Scugog | Port Perry | $259K |
| Operation Sharing of Woodstock | Woodstock | $1.6M |
| Operation Smile Canada Foundation | Toronto | $21.9M |
| Operation Springboard | Toronto | $12.1M |
| Opération Surveillance Anjou (OSA) | Anjou | — |
| Operation Trackshoes Society | Victoria | $5,655 |
| Operation Turkey Drive | Oshawa | $53K |
| Operation Victory Ministries | Don Mills | — |
| Operation Walk Canada Inc. | London | $250K |
| Operation Walk (Manitoba) Inc. | Winnipeg | $225K |
| Operators Without Borders | Vancouver | $48K |
| Opokaa'Sin Early Intervention Society | Stand-Off | $2.7M |
| Opportunities for Employment Inc. | Winnipeg | $7.6M |
| Opportunities for Independence Inc. | Winnipeg | $5.5M |
| Opportunities for Latin American Children | Toronto | $59 |
| Opportunities United Community Initiative | Windsor | $1M |
| Opportunity Enterprises | Ponoka | $57K |
| Opportunity for Advancement | Toronto | $731K |
| Opportunity Home Treatment & Recovery Centre | Drayton Valley | $483K |
| Opportunity International Canada Foundation/fondation Opportunité Internationale Canada | Oakville | $430K |
| Opportunity International Canada/opportunité Internationale Canada | Oakville | $2.1M |
| Opportunity Works Calgary Incorporated | Calgary | — |
| Optica - A Centre For Contemporary Art - Optica - un centre au service de l'art contemporain | Montreal | $423K |
| Optimist Club of Keswick Inc Charitable Trust | Keswick | $59K |
| Optimist Club of Kitchener Waterloo Charitable Trust | Waterloo | $41K |
| Optimist Club of Stratford Charitable Foundation | Stratford | $39K |
| Optimist Club of Thorndale-Youth | Thorndale | $39K |
| Optimist Clubs Foundation of Winnipeg Inc. | Winnipeg | $5,916 |
| Optimum Guatemalan Relief Canada Inc. | Huntsville | $30K |
| Optimum Help Foundation | Mississauga | $100K |
| Option Femmes Emploi | Gatineau | $789K |
| Option: une alternative à la violence conjugale | Montreal | $967K |
| Options Community Services Society | Vancouver | $67.6M |
| Options For Independent Living and Development | Hamilton | $504K |
| Options for Sexual Health | Vancouver | $2.2M |
| Options Grosseses | Quebec | $64K |
| Options Housing Incorporated | Ottawa | $4.6M |
| Options Mississauga Print and Office Services | Mississauga | $476K |
| Options Northwest Personal Support Services | Thunder Bay | $21.4M |
| Options Pathways & Transitions Inc. | Winnipeg | $2M |
| Options Pregnancy Center Resources and Lifestyle Coaching Inc. | Regina | $216K |
| Optometry Giving Sight | Calgary | $522K |
| Opus 1 Singers | Cobble Hill | $18K |
| Or Chadash | North York | — |
| Or Chaim Minyan | Toronto | $220K |
| Or Hadash Synagogue | Newmarket | $32K |
| Or Haneshamah - Ottawa's Reconstructionist Community | Ottawa | $204K |
| Or Shalom - Jewish Spiritual Community Association | Vancouver | $1.5M |
| Ora-Organization for the Rescue of Animals | Mount Albert | $2,392 |
| Oraison du Coeur | Saint-Alphonse-Rodriguez | $21K |
| Oral Roberts Evangelistic Association of Canada | North York | $718K |
| Orange and Blue Research | Whitby | — |
| Orange Noyée | Montreal | $410K |
| Orange Tree Foundation - Canada | Oakville | $1,748 |
| Orangedale - Gillis Cove Cemetery | Orangedale | — |
| Orangedale Improvement Association | Orangedale | $2,950 |
| Orangedale Station Association | Orangedale | $9,869 |
| Orangeville Baptist Church | Orangeville | $1.9M |