| CAOS Linux | — | 2004 | — |
| CarbonROM | — | — | — |
| Cdlinux.pl | — | 2001 | GNU General Public License |
| CentOS | — | 2004 | GNU General Public License |
| CentOS Stream | Red Hat, IBM | 2019 | GNU General Public License |
| Chakra Linux | — | — | GNU General Public License |
| ChaletOS | — | — | — |
| CHAOS | — | — | — |
| Chapeau | — | — | — |
| Chimera Linux | — | — | — |
| ChimeraOS | — | — | — |
| ChromeOS | Google | — | proprietary license |
| ChromeOS Flex | Neverware | 2015 | — |
| ChromiumOS | Google | 2009 | BSD licenses |
| Cinux | — | — | — |
| Clear Linux OS | Intel | — | — |
| ClearOS | — | — | GNU General Public License |
| Clockwork OS | ClockworkPi | — | — |
| CloudLinux | — | — | — |
| Cobuntu | — | — | — |
| Colebuntu | — | — | — |
| College Linux | — | — | — |
| Commodore OS | Commodore USA | 2010 | GNU General Public License |
| Compute Node Linux | Cray | — | — |
| Condres OS | — | — | — |
| Conectiva | — | — | — |
| ConnochaetOS | Henry Jensen | — | — |
| Container Linux | — | — | Apache License |
| Corel Linux | Corel | — | GNU General Public License |
| Coyote Linux | — | — | GNU General Public License |
| Cp6linux | — | — | — |
| CROWZ | — | — | — |
| CrunchBang Linux | — | — | GNU General Public License |
| CrunchBang Plus Plus | — | — | — |
| CRUX | — | — | GNU General Public License |
| Cub Linux | — | — | — |
| Cubuntu | — | — | — |
| Cucumber Linux | — | — | — |
| CutefishOS | — | — | — |
| CyanogenMod | CYNGN Inc. | 2009 | Android Open Source Project, Apache License, GNU General Public License |
| CyberOS | — | — | — |
| Damn Small Linux | John Andrews | — | GNU General Public License |
| Damn Vulnerable Linux | — | — | — |
| Darik's Boot and Nuke | — | — | GNU General Public License |
| Darkstar Linux | — | — | — |
| DAVIX | — | — | — |
| Dawn | — | — | — |
| Daylight Linux | — | — | — |