| Silverball Studios | Developer | |
| Silverbirch Studios | Developer | |
| Silverbird | Publisher | |
| Silverbird Software | Publisher | |
| Silverm | Developer | |
| Silversober | Developer | |
| Silversoft | Publisher | |
| Silversoft Ltd | Publisher | |
| Silverstring Media | Developer | |
| Silverware Games | Developer | |
| Silvijn | Developer | |
| Silvio257 | Developer | |
| SilviuZLD | Developer | |
| Sim0wn3d | Developer | |
| SimBin | Developer | |
| SimBin Studios | DeveloperPublisher | |
| SimDevs | DeveloperPublisher | |
| SimFabric | DeveloperPublisher | |
| SimGraph | Developer | |
| SimLab Games | Developer | |
| SimSoftGames | Developer | |
| SimTex | Developer | |
| Sima | Developer | |
| Sima Games | Developer | |
| Simbi | Developer | |
| Simbin | Developer | |
| Simbiosis Interactive | Developer | |
| SimeStudios | Developer | |
| Simex | Developer | |
| Similia | Developer | |
| Similis | Developer | |
| Siminu | Developer | |
| Simis | Developer | |
| Simmer Software (Jeff Calder, George Calvert, Andy Wynd) | Developer | |
| Simo K. Tuima | Developer | |
| Simogo | DeveloperPublisher | |
| Simon & Schuster | DeveloperPublisher | |
| Simon & Schuster Interactive | DeveloperPublisher | |
| Simon 'GoZz' Mielcarek | Developer | |
| Simon Brattel | Developer | |
| Simon Butler | Developer | |
| Simon Chauvin | Developer | |
| Simon Chen | Developer | |
| Simon Cobb | Developer | |
| Simon Conway | Developer | |
| Simon Creative | Developer | |
| Simon Daniels | Developer | |
| Simon Dunstan | Developer | |
| Simon Ernst | Developer | |
| Simon Freeman | Developer | |