| Name | Abrv. | Local# | Place of Work |
|---|---|---|---|
| Amalgamated Transit Union | ATU | 1320 | Peterborough Transit |
| Public Service Alliance of Canada Canada Employment and Immigration Union |
CEIU | 628 | EI Office |
| Canadian Auto Workers | CAW | 524 | GE Canada |
| CAW | 830 | Hunt Brothers, Pleasant Meadow Manor (Norwood), Cruikshank Cleaners | |
| CAW | 1987 | Canada Talc, Messier-Dowty, NHB Pan Oston, Ventra Plastics | |
| CAW | 1996 | Pepsico Canada | |
| Canadian Office and Professional Employees | COPE | 343 | Safety Centre Representative (associate member) |
| Canadian Union of Postal Workers | CUPW | 590 | Canada Post Rural and Urban Operations and Retail |
| Canadian Union of Public Employees | CUPE | 131 | Fairhaven Home for the Aged |
| CUPE | 1000 | Ontario Power Generation, Hydro One | |
| CUPE | 1453 | Peterborough, Victoria, Northumberland, Clarington Catholic District School Board Support Staff | |
| CUPE | 1833 | Peterborough Public Library | |
| CUPE | 1943 | Peterborough Regional Health Centre | |
| CUPE | 2280 | St. Joseph's at Fleming | |
| CUPE | 3908 Unit 1 |
Trent University Part Time Instructors | |
| CUPE | 3908 Unit 2 |
Trent University Academic Assistants | |
| CUPE | 4911 | Paramedics, County of Peterborough | |
| Communications, Energy and Paperworkers Union | CEP | 29 X | Bell Canada |
| CEP | 247 | AIL Canada Insurance | |
| CEP | 599 | GE Canada | |
| CEP | 685 | Genpak Processors | |
| International Association of Machinists and Aerospace Workers | IAMAW | 905 | Hispano-Suiza Canada, Nefab |
| International Brotherhood of Electrical Workers | IBEW | 636 | Representing 112 employees of Peterborough Utilities |
| International Federation of Professional and Technical Engineers | IFPTE | 164 | GE Canada Draftpersons |
| Ontario English Catholic Teachers Association | OECTA | PVNC Unit | Ontario Roman Catholic School Teachers |
| Ontario Public Service Employees Union | OPSEU | 308 | representing Peterborough staff at the Ministry of Community and Social Services, the Ministry of Education, the Ministry of the Environment, the Ministry of Food and Agriculture, the Ministry of Housing (Land Registry Office), the Ministry of Labour, the Ministry of Public Safety and Security (formerly Attorney-General and Corrections) and the Ministry of Transportation |
| OPSEU | 315 | Peterborough Community Access Centre | |
| OPSEU | 373 | Peterborough Regional Health Centre | |
| OPSEU | 379 | Liquor Board Employees Division representing LCBO staff in east central Ontario stores | |
| OPSEU | 345 | Peterborough Regional Health Centre | |
| OPSEU | 351 | Support staff at Sir Sandford Fleming College | |
| OPSEU | 352 | Faculty at Sir Sandford Fleming College | |
| OPSEU | 358 | Peterborough and District Association for Community Living | |
| OPSEU | 362 | Ministry of Natural Resources | |
| OPSEU | 365 | Support Staff at Trent University | |
| Ontario Secondary School Teachers Federation | OSSTF | Dist 14 | Public Secondary School Teachers |
| Service Employees International Union | SEIU | 1 Canada | Extendicare Lakefield, Extendicare Peterborough, Kawartha Quality Care, Peterborough Manor, Riverview Manor, Rubidge Hall, Springville Nursing Home, Peterborough Humane Society |
| SEIU | 2 BGPWU | Representing workers at Kawartha Downs Raceway and Slots in Fraserville | |
| Trent University Faculty Association | TUFA | 259 | Trent University |
| United Food and Commercial Workers Union | UFCW | 175 & 663 | A&P, G.U.S., Havelock IGA, Minute Maid, Morello's Independent Grocer, United Canadian Malt, Zellers |