| Artist | Year at the Gathering |
| C+C Music Factory | 2019 |
| Cage | 2017 |
| Cameron Buchholtz | 2014, 2015 |
| Cannibal Corpse | 2014 |
| Cash Reap | 2013, 2014 |
| Caskey | 2014 |
| Caucasian Refuse | 2007 |
| Cellar Mannequin | 2008, 2009 |
| Cellblock M | 2006 |
| Cemetery High | 2018 |
| CES Cru | 2014, 2016 |
| Charlie Murphy | 2005, 2013 |
| Cheech & Chong | 2012 |
| Chiiirp | 2017, 2018 |
| Chop Meat | 2012 |
| Chop Shop | 2008, 2009, 2012, 2017 |
| Church of Hate | 2006 |
| Cid Voorheez | 2006, 2007, 2009 |
| City Morgue | 2019 |
| City Limits | 2015 |
| CKY | 2011, 2018 |
| ClaAs | 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 |
| Clooner | 2022 |
| Clownvis Presley | 2018, 2019 |
| C-Mob | 2019 |
| Cody Manson | 2021 |
| Co-Effusion | 2006 |
| Cognito | 2012 |
| Cold 187um | 2012 |
| Colt Cabana | 2011 |
| Coolio | 2009, 2010 |
| Critical Bill | 2010, 2011, 2012 |
| CRSMN | 2009 |
| Crucifix | 2014 |
| Cryptic Soljas | 2007 |
| Cryptic Wisdom | 2014 |
| Cybertronic Spree | 2019 |
| Cykosomatik | 2013 |
| Cypress Hill | 2014 |
