| giw | Graph-in-the-Box for Windows Presentation |
| glk | GenStat ODBC Export Link |
| gly | Microsoft Word Glossary Data |
| gml | Geography Markup Language Document |
| gmp | GEM Desktop Publisher Document |
| gnh | GravoStyle Design Document |
| gnu | Gnuplot Input File |
| gnumeric | Gnumeric Spreadsheet |
| gofin | Druki Gofin Form Document |
| gom | gOpenMol Model |
| gp | Guitar Pro 7 Tabulature |
| gp3 | Guitar Pro Tabulature |
| gp4 | Guitar Pro Tabulature |
| gp5 | Guitar Pro Tabulature |
| gp6 | Guitar Pro 6 Tabulature |
| gpl | Gnuplot Input File |
| gplt | Gnuplot Input File |
| gpp | Serif Graphics Plus Document |
| gpx | Guitar Pro 6 Tabulature |
| gq | Epson Page Description Language Document |
| gqsx | Microsoft Office SmartArt Styles |
| gra | Microsoft Graph Chart |
| grade | GradeStat Document |
| graffle | OmniGraffle Drawing |
| graphml | GraphML Document |
| graphmlz | GraphML Compressed Document |
| grf | GEM Graph Document |
| grf | Grapher Document |
| grg | GreatFamily Graphic Gallery |
| grs | Esko Packedge GRS Document |
| gsa | Microsoft Office Groove 2007 Archived Workspace |
| gsb | Grisbi Document |
| gsd | Profibus Generic Station Description |
| gsh | GenStat Spreadsheet |
| gsheet | Google Drive Sheet |