| Name | City | St. | Country | Email | Scope | Network | Update | Map |
| Clean Water Action Alliance of MN | Minneapolis | Minnesota | United States | Email | State | Network | 06-13
2005 |  |
| Clinton Global Initiative University | New York | New York | United States | Email | International | | 01-24
2008 | |
| Clinton Twp. Clean Water Actio | Clinton Twp. | Michigan | United States | Email | Local | | 08-06
2006 | |
| Close Up Foundation | Alexandria | Virginia | United States | Email | National | | 08-06
2007 | |
| Club Activism | Poultney | Vermont | United States | | Local | | 02-22
2009 | |
| Coalition Against War - Stony Brook University | Stony Brook | New York | United States | Email | Local | | 12-04
2002 | |
| Coalition for Student & Academic Rights | Solebury | Pennsylvania | United States | Email | National | | 04-07
2005 | |
| Cobbs Creek Community Environmental Education Center | Philadelphia | Pennsylvania | United States | Email | Metro | | 09-15
2004 | |
| COD Democrats | Lisle | Illinois | United States | Email | Local | | 10-18
2004 | |
| CODEPINK: Women for Peace | | | United States | Email | National | Network | 11-08
2005 | |
| Codewit Global Network | | | Finland | Email | International | Network | 03-22
2009 | |
| CofC SDS | Charleston | South Carolina | United States | Email | Local | | 04-01
2008 | |
| COLA - Cornell Organization for Labor Action | Ithaca | New York | United States | Email | Local | | 03-16
2004 | |
| Colby-Sawyer Coalition for Peace & Justice | New London | New Hampshire | United States | Email | Local | | 11-06
2004 | |
| Colgate Advocates | Hamilton | New York | United States | Email | Local | | 09-10
2006 | |
| Collegiate Forum | | | United States | Email | International | Network | 03-05
2006 | |
| Collegiate Liberals of America | Bradford | Pennsylvania | United States | Email | State | Network | 01-28
2004 | |
| Colorado Association for Student Representation | Fort Collins | Colorado | United States | Email | State | | 10-01
2004 | |
| Colorado Campaign for Middle East Peace | Denver | Colorado | United States | Email | State | | 01-04
2004 | |
| Columbia ACLU | New York | New York | United States | Email | Local | | 04-17
2004 | |
