Amalgamated Transit Union
- ATU 107
Canadian Office & Professional Employees
- COPE 343
- COPE 527
Canadian Union of Public Employees
- CUPE 932
- CUPE 1000
- CUPE 1404
- CUPE 1281
- CUPE 3396
- CUPE 3906
- CUPE 3943
- CUPE 4153
- CUPE 4207
- CUPE 5167
- CUPE 7800
Canadian Union of Postal Workers
- CUPW 548
Elementary Teachers of Ontario
- HWETL
- HWOTL
- HWTEL-DECE (ETFO)
Canadian Federation of Musicians
- HMG 294 (AFM)
International Association of Machinists and Aerospace Workers
- IAMAW 1295
International Alliance of Theatrical Stage Employees
- IATSE 129
International Brotherhood Of Boilermakers
- Local 128
International Brotherhood of Electrical Workers
- Local 105
International Association of Heat and Frost Insulators and Allied Workers
- Local 95
International Union of Operating Engineers
- Local 772
- Local 793
Ontario English Catholic Teachers Association
- Hamilton-Wentworth (Elementary)
Ontario Public Service Employees Union
- OPSEU 281
- OPSEU 201
- OPSEU 202
- OPSEU 206
- OPSEU 240
- OPSEU 241
- OPSEU 262
- OPSEU 287
Ontario Secondary School Teachers Federation
- OSSTF 21 T/OT
- OSSTF 21 OCTU
- OSSTF 21 PSSP
- OSSTF 21 PECW
- OSSTF 21 ESL
- OSSTF 32 Unit 64
Public Service Alliance of Canada
- PSAC Hamilton
United Association of Journeymen and Apprentices of the Plumbing, Pipefitting and Sprinkler Fitting Industry
- UA 67
Service Employees International Union
- SEIU Healthcare
- SEIU 2
Society of United Professionals
- Local 160
Teamsters
- Local 879
United Food and Commercial Workers Union
- UFCW 232
- UFCW 175/633
- UFCW 633
United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union
- USW 1005
- USW 14162
- USW 16506
- USW 2308
- USW 4153
- USW 5328
- USW 6920
- USW 7135
- USW 8782
- USW 8925
Workers United Canada
- Local 210C