| Citadel Studios | United States | 2013 | 1 | 1 |
| City Connection | Japan | April 2005 | 20 | 22 |
| Clap Hanz | Japan | April 2, 1998 | 9 | 1 |
| Claranova | France | — | — | 1 |
| Claytechworks | Japan | July 4, 2018 | 1 | — |
| Clear River Games | Sweden | 2020 | — | 4 |
| Cleversan Games | Poland | — | 3 | — |
| ClickBoom | Canada | 1994 | — | 1 |
| Clickteam | — | 1993 | 1 | 2 |
| Cliffhanger Productions | Canada | — | 1 | — |
| Climax Entertainment | Japan | 1990 | 2 | — |
| Clochette | Japan | — | 1 | 1 |
| ClockStone | Austria | 2006 | 7 | — |
| Clockup | Japan | 2002 | 4 | 4 |
| Clockwork Origins | Germany | — | 2 | 2 |
| Clouded Leopard Entertainment | — | August 16, 2019 | — | 4 |
| Cloudgine | United Kingdom | — | 1 | — |
| Clover Bite | Israel | 2014 | 1 | — |
| Clover Studio | Japan | July 2004 | 1 | — |
| CM Games | Estonia | 2010 | 1 | 1 |
| Coatsink | United Kingdom | 2009 | 3 | 7 |
| Cobra Mobile | United Kingdom | April 7, 2005 | 2 | 2 |
| Cobrasoft | France | 1985 | — | 1 |
| Cococucumber | Canada | 2014 | 3 | 3 |
| Cocodrilo Dog | Australia | — | 1 | — |
| Coconut Island Games | People's Republic of China | 2009 | — | 1 |
| Coconuts Japan | Japan | November 1985 | 1 | 1 |
| Code Mystics | Canada | 2009 | 2 | — |
| CodeCombat | United States | April 2013 | 1 | — |
| Codemasters | United Kingdom | 1986 | 31 | 59 |
| Coffee Addict Studio | Brazil | January 10, 2014 | 1 | — |
| Coffee Stain Studios | Sweden | 2010 | — | 2 |
| COGNOSPHERE | Singapore | 2021 | — | 5 |
| Cognosphere | People's Republic of China | February 13, 2012 | 9 | 7 |
| Cohort Studios | United Kingdom | March 2006 | 2 | — |
| Cokem International | — | 2000 | — | 1 |
| Coktel Vision | France | 1984 | 9 | 5 |
| ColePowered Games | United Kingdom | 2011 | 1 | — |
| Color Dreams | United States | 1988 | — | 1 |
| Colorful Palette | Japan | June 2018 | 1 | — |
| Colossus Game Studio | Brazil | 2015 | 7 | 7 |
| Colour Colliders | Austria | — | 1 | — |
| COMADSOFT | Poland | February 10, 2014 | 1 | 1 |
| Combat Waffle Studios | — | — | 1 | — |
| CommaVid | — | 1981 | 1 | 1 |
| Commodore International | United States | October 10, 1958 | — | 1 |
| Compedia | — | 1988 | 1 | — |
| Compulsion Games | Canada | 2009 | 1 | — |
| Computer Emuzone Games Studio | Spain | 2003 | 1 | — |
| Con Artist Games | Australia | — | 1 | — |
| Concept by Utrecht School of the Arts | Netherlands | — | 1 | — |
| Conradical Games | Switzerland | — | 3 | 1 |
| Conspiracy Entertainment | United States | 1997 | — | 2 |
| Contrail | — | October 16, 1997 | — | — |
| Cooking & Publishing | Spain | — | 2 | 3 |
| Cooking Mama Limited | Japan | — | 8 | — |
| Core Design | United Kingdom | 1988 | 12 | — |
| Corecell Technology Co. Ltd. | Thailand | 2002 | 1 | — |
| Coreplay | Germany | — | 1 | — |
| Cornfox & Bros. | Finland | — | 2 | 1 |
| COSEN Co., Ltd. | Japan | 2014 | — | 9 |
| Cosmi Corporation | United States | — | — | 9 |
| Cosmic Boop | United Kingdom | August 12, 2019 | 1 | — |
| Cosmonaut Studios | United Kingdom | 2015 | 1 | — |
| Cotton Game | People's Republic of China | 2013 | 5 | 4 |
| Covenant.dev | Poland | 2020 | 1 | 1 |
| COVER Corporation | Japan | June 13, 2016 | 1 | 2 |
| COWCAT Games | France | — | 1 | 1 |
| Cozy Bee Games | Canada | 2021 | 3 | 2 |
| Cpc-power.com | France | — | — | 1 |
| Cracked Heads Games | Russia | — | 1 | — |
| Cradle Games | Canada | April 2, 2015 | 2 | — |
| Crafting Legends | Germany | — | 1 | 1 |
| CRAFTWORK | — | — | — | 1 |
| Cranberry Production | Germany | 1997 | 3 | — |
| Craneballs | Czech Republic | 2008 | 1 | — |
| Crave Entertainment | United States | 1997 | 1 | 20 |
| Crawfish Interactive | United Kingdom | 1997 | 2 | — |
| Crazy Labs | Israel | 2011 | 2 | 2 |
| Crazy Monkey Studios | Belgium | 2010 | 4 | 4 |
| CrazyBunch | Germany | September 2014 | 3 | — |
| Crazysoft | Cyprus | — | 2 | 2 |
| Crea-Tech | Japan | 1988 | 4 | — |
| Creashock studios | Ukraine | — | 1 | 1 |
| Creat Studios | Russia | 1990 | 3 | 1 |
| Creative Assembly | United Kingdom | August 18, 1987 | 25 | — |
| Creative Assembly Sofia | — | 2001 | 1 | — |
| Creative Capers Entertainment | United States | 1989 | 1 | — |
| Creative Games & Computer Graphics Corporation | Taiwan | — | 1 | — |
| CreativeForge Games | Poland | 2011 | 3 | 5 |
| Creatures | Japan | November 8, 1995 | 11 | 3 |
| Crema | Spain | 2012 | 1 | — |
| Creoteam | Ukraine | 2005 | 1 | 1 |
| Crescent Moon Games | United States | 2009 | — | 9 |
| CreSpirit | Taiwan | — | 1 | 1 |
| CRI Middleware | Japan | August 2001 | 2 | — |
| Criterion Games | United Kingdom | 1993 | 18 | — |
| Critical Games | Australia | — | 1 | 1 |
| CRL Group | United Kingdom | 1982 | 3 | 4 |
| CROOZ | Japan | May 24, 2001 | 1 | — |