| Abbreviation | Definition |
|---|---|
| COSATU | Corrupt Overweight Silly Arrogant Toads Union |
| COSATU | Council Of South African Trade Unions |
| COTU | Central Organization of Trade Unions |
| COWU | Coalition of Workers Unions |
| CPA | Canadian Police Association (also CPA-ACP) |
| CPA-ACP | Canadian Police Association - Association Canadienne Policiers |
| CPBU | China Professional Boxing Union |
| CPCU | Carolina Postal Credit Union |
| CPNU | Coloured People Nation Union |
| CPSU | Commonwealth Public Sector Union |
| CPSU | Communist Party of the Soviet Union |
| CPSU | Community and Public Sector Union |
| CPSU | Community Public Sector Union |
| CPSU | Confederation of Public Sector Unions |
| CRCU | Cape Regional Credit Union |
| CRFU | Canterbury Rugby Football Union |
| CSC | Conf??d??ration des Syndicats Chr??tiens |
| CSC | Confédération des Syndicats Chrétiens |
| CSCU | Card Services for Credit Unions |
| CSEU | Confederation of Shipbuilding and Engineering Unions |