| GAA | HL | 357 | Business Express (Delta Connection) |
| GAE | Grand Aire Express | ||
| GAI | 3R | Gromov Air | |
| GAL | GP | Gemini Airlines | |
| GAO | DC | Golden Air Flyg | |
| GAP | 2P | 211 | Air Philippines |
| GAW | 866 | Gambia International Airways | |
| GAZ | Global Aviation | ||
| GBK | GY | 013 | Gabon Airlines |
| GBL | GT | 171 | GB Airways |
| GCA | IF | Great China Airlines | |
| GCB | Lina Congo | ||
| GCK | Aerogem Aviation Ltd | ||
| GCO | GR | 358 | Gemini Air Cargo |
| GCP | 6P | 779 | DAC Air SA |
| GDI | 8L | Grand International Airways Inc | |
| GEA | Georgia Air | ||
| GEC | LH | 020 | Lufthansa Cargo |
| GEG | 3P | 684 | Georgian Airlines |
| GEO | DA | 500 | Air Georgia |
| GFA | GF | 072 | Gulf Air |
| GFI | 8B | Caribbean Star Airlines | |
| GFT | 3M | 449 | Gulfstream International Airlines |
| GGN | ZX | Air Georgian/Georgian Express | |
| GGZ | Global Georgian Airways | ||
| GHA | GH | 237 | Ghana Airways |
| GHN | Air Ghana | ||
| GIA | GA | 126 | Garuda Indonesia |
| GIB | GI | 093 | Air Guinee |
| GIF | G7 | Guinea Airlines | |
| GIL | 9C | 786 | Gill Airways |
| GIP | 2U | 454 | Air Guinee Express |
| GJB | TY | 348 | Trans Air Link |
| GJT | 8K | Girjet | |
| GLA | ZK | 846 | Great Lakes Aviation Ltd |
| GLD | Golden Star Air Cargo | ||
| GLO | G9 | GOL Transportes Aeros | |
| GLR | 9M | 634 | Central Mountain Air |
| GMA | Gama Aviation | ||
| GMG | Z5 | 009 | GMG Airlines |
| GMI | ST | Germania Fluggesellschaft | |
| GNF | G7 | Gandalf Airlines | |
| GNR | GC | 034 | Gambia International Airlines |
| GNT | II | 593 | Business Air |
| GOE | GO | 333 | GO |
| GOW | G8 | GoAir | |
| GRA | Great American Airways | ||
| GRE | Greece Airways | ||
| GRL | GL | 631 | Air Greenland |
| GRO | LL | 902 | Lineas Aereas Allegro |
| GRR | Air Zodiac | ||
| GSM | Y2 | Flyglobespan | |
| GSS | Global Supply Systems | ||
| GTI | 5Y | 369 | Atlas Air |
| GTK | GTI Airlines | ||
| GTV | KG | 854 | Aerogaviota |
| GTY | NC | National Aviation Company | |
| GUG | GU | 240 | TACA/Aviateca |
| GUJ | G8 | Gujurat Airways | |
| GWI | 4U | Germanwings | |
| GWL | IJ | 989 | Great Wall Airlines |
| GXY | J7 | Galaxy Airlines | |
| GYA | GY | Guyana Airways | |
| GZD | Grizodubova Air Company | ||
| GZP | OC | Gazpromavia Aviation Company |