| Sigma | Publisher | |
| Sigma Enterprises | DeveloperPublisher | |
| Sigma Enterprises Inc. | Publisher | |
| Sigma Enterprises JP | Publisher | |
| Sigma EnterprisesJP | Publisher | |
| Sigma Pro-Tech | Developer | |
| Sigma Team | DeveloperPublisher | |
| SigmaSuccour | Developer | |
| Sign hunter | Developer | |
| Signa Works | Developer | |
| Signal Studios | Developer | |
| Signalised | Developer | |
| Signed and Sealed With a Kiss | Developer | |
| Significant Games | Developer | |
| Significant Gravitas | Developer | |
| Signol_Games | Developer | |
| Sigono | Developer | |
| Sigrids Änglar | Developer | |
| Sigrún Tinna Gissurardóttir | Developer | |
| Sigtrap Games | Developer | |
| Sigur Studio | Developer | |
| Siieg | Developer | |
| Siile | Developer | |
| Siisi4 | Developer | |
| Sijawa Production | Developer | |
| Sik | Developer | |
| Sikeology | Developer | |
| Silas Grarup | Developer | |
| Silas Warner | Developer | |
| Silasmakegame | Developer | |
| Silasman | Developer | |
| Silberspiele | Developer | |
| SilbinaryWolf | Developer | |
| Silence | Developer | |
| SilenceArts | Developer | |
| Sileni Studios | Developer | |
| Silent Dreams | Developer | |
| Silent Future | Developer | |
| Silent Interactive | Developer | |
| Silent Knight Games | Developer | |
| Silent Lizard | Developer | |
| Silent Minstrel | Developer | |
| Silent Software | Developer | |
| Silent Software Inc | Developer | |
| Silent Software, Inc. | Developer | |
| Silent Tower Games | Developer | |
| SilentYetJudgy | Developer | |
| Silentman | Developer | |
| Silesia Games | DeveloperPublisher | |
| Silhouette Software (John F Cain, Simon Price) | Developer | |