| G | Gravitational acceleration |
| G | Gravity |
| G | Conductance |
| G | Giga (10^9) |
| G | Gravitational force |
| GAC | Granular Activated Carbon |
| GAIM | GSM Analog Interface Module |
| GAL | Gate Array Logic |
| GASAD | Gate And Source And Drain |
| GATE | Graduate Aptitude Test in Engineering |
| GB | Giga Byte |
| GC | Gas Chromatography; Gravimetric Calibrator |
| GCC | Generic Cell Controller |
| GCD | Gas Chromatography Distillation |
| GCMS | Gas Chromatography Mass Spectroscopy |
| GCPW | Grounded CoPlanar Waveguide |
| GD | Glow Discharge |
| GDMS | Glow Discharge Mass Spectrometry |
| GDS | Graphical Design System; Graphical Design Software |
| GEDIS | Gateway Electronic Data Interchange Services |
| GEM | Generic Equipment Model; Ventura/GEM drawing image format |
| GEMS | Gateway Electronic Mail Service |
| GEMVS | GEM Verification System |
| GEO | Geostationary Earth Orbit |
| GES | Generic Equipment Simulator |
| GFAAS | Graphite Furnace Atomic Absorption Spectrometry/spectroscopy |
| GFC | Gas Filter Correlation |
| GFCI | Ground Fault Circuit Interrupter |
| GIAS | Gateway Internet Access Services |
| GIF | Graphic Interchange Format |
| GIF | Gatan Imaging Filter |
| GILD | Gas Immersion Laser Doping |
| GIST | Graphics and Intelligence-based Script Technology |
| GLC | Gas Liquid Chromatography |
| GLU | General Logic Unit |
| GLUE | Generally 7400-series chips to glue (connect) VLSI-chips together |
| GMA | Gas Metal Arc (welding) |
| GML | Geospatial Markup Language |
| GMR | Giant Magneto Resistant |
| GNOS | GaN-on-Sapphire |
| GOI | Gate Oxide Integrity; GaAs On Insulator |
| GOSIP | Government Open Systems Interconnection Profile |
| GPE | Gas Phase Etching |
| GPIB | General-Purpose Interface Bus |
| GPO | Gilbert Push-On Connector (TM) |
| GPON | Gigabit Passive Optical Network |
| GPRS | General Packet Radio Service |
| GPRS | General Packet Radio Service |
| GPS | Global Positioning System |
| GPS | Global Positioning System |
| GPSS | Gateway Packet Switching System |
| GRINSCH | GRaded INdex Separate Confinement Heterostructure |
| GSM | Global System Mobile |
| GSM | Global Systems for Mobile (communications) |
| GSO | Geo-Synchronous Orbit |
| GSPID | Gain-Scheduled Proportional Integro-Differential |
| GTA | Gas Tungsten Arc |
| GTO | Gate Turn Off (thyristor) |
| GTS | GEM Test System |
| GUI | Graphical User Interface |
| GUI | Graphical User Interface |
| GWIM | Global Warming Impact Model |
| Ga | Gallium; Available Gain |
| GaAs | Gallium Arsenide |
| Ge | Germanium |
| GHz | GigaHertz (1,000,000,000 Hz) |
| Gmax | Maximum Gain |
| GND | Ground (voltage level) |
| Gopt | Gamma Optimum (generator impedance) |
