| North York Centre Street Improvement Projects | active | — | — | — |
| North York Women's Shelter | Complete | Growth Related C05 | 07 | $12.0M |
| Northeast London Catholic Elementary School | Under construction | Growth Related C05 | CW | $11.7M |
| Northeastern Manitoulin & The Islands Asset Management Project | Approved | — | — | $4K |
| Northern Bruce Peninsula Asset Management Project | Approved | — | — | $4K |
| Northern College Expansion | Complete | Growth Related C05 | CW | $11.7M |
| Northern Dancer Public Elementary School | Complete | State of Good Repair C03 | CW | $12.2M |
| Northern Lights Secondary School | Complete | State of Good Repair C03 | CW | $1.2M |
| Northglen Catholic Elementary School | Under construction | — | — | $26.2M |
| Northglen Public Elementary School | Under construction | State of Good Repair C03 | CW | $36.8M |
| Northumberland County Asset Management Project | Approved | — | — | $11K |
| Northwest London Public Elementary School | Under construction | Service Improvement and Enhancement C04 | CW | $28.7M |
| Norwich Asset Management Project | Approved | — | — | $5K |
| Norwood District Public Secondary School | Complete | Service Improvement and Enhancement C04 | CW | $950K |
| Notre Dame Addition | Planning | Growth Related C05 | 15 | $3.9M |
| Notre Dame Catholic Elementary and Secondary School | Complete | State of Good Repair C03 | CW | $6.6M |
| Notre Dame Catholic Elementary School | Complete | — | — | $2.1M |
| Notre Dame Catholic High School | Under construction | — | — | $5.5M |
| Nouvelle école élémentaire Leitrim | Planning | — | — | $20.2M |
| O’Connor Drive Improvements | active | — | — | — |
| Oak Ridges Public Secondary School | Planning | State of Good Repair C03 | CW | $45.4M |
| Oakridge Public Elementary School | Complete | Service Improvement and Enhancement C04 | CW | $1.5M |
| Oakridge Streets Plan | active | — | — | — |
| Oakville NE 1 Public Secondary School | Under construction | Service Improvement and Enhancement C04 | CW | $69.6M |
| Oakville NE 2 Public Elementary School | Complete | State of Good Repair C03 | CW | $18.7M |
| Oakwood Public Elementary School | Complete | Service Improvement and Enhancement C04 | CW | $1.0M |
| Oakwood Village Streets Plan | active | — | — | — |
| ODOUR CONTROL IMPLEMENTATION - PHASE 1 | Wastewater Program | Legislated C02 | CW | $10K |
| On-Grade Paving Rehabilitation - SOGR | Toronto Transit Commission | State of Good Repair C03 | CW | $22K |
| Ontario Federation of Snowmobile Signage Project | Approved | — | — | $100K |
| Ontario Highways - Niagara and Sarnia | Approved | — | — | $160.9M |
| Ontario Line | Under Construction | Transit | Toronto Centre | $10.9B |
| Oodenawi Public Elementary School | Complete | Service Improvement and Enhancement C04 | CW | $12.4M |
| OP Conformity Review | City Planning | Legislated C02 | CW | $260 |
| Opasatika Asset Management Project | Approved | — | — | $3K |
| Open Door Non-TCA | Housing Secretariat | Growth Related C05 | CW | $97 |
| Open Roads Public Elementary School | Complete | State of Good Repair C03 | CW | $361K |
| Operations and Environmental Services Asset Management | Approved | — | — | $14K |
| OPERATIONS CONTROL CENTRE - CONSTRUCTION | Wastewater Program | Service Improvement and Enhancement C04 | CW | $818 |
| Orchard Park Public Elementary School | Complete | State of Good Repair C03 | CW | $1.5M |
| ORGANIC PROCESSING FACILITY | Solid Waste Management Services | Growth Related C05 | CW | $102K |
| Orillia Public Elementary School | Planning | Service Improvement and Enhancement C04 | CW | $9.0M |
| Orillia Public Secondary School | Complete | Service Improvement and Enhancement C04 | CW | $30.4M |
| Orillia-Asset Management Project | Approved | — | — | $12K |
| Oro Medonte Public Elementary School | Under construction | State of Good Repair C03 | CW | $19.6M |
| Orono Public Elementary School | Complete | Service Improvement and Enhancement C04 | CW | $745K |
| Ossington Avenue Safety & Streetscaping Improvements | active | roads | — | — |
| Other Bldgs and Structures SI | Toronto Transit Commission | Service Improvement and Enhancement C04 | CW | $1.9M |
| Other Service Planning - Legislated | Toronto Transit Commission | Legislated C02 | CW | $11K |
| Other Service Planning - SOGR | Toronto Transit Commission | State of Good Repair C03 | CW | $11K |