LGS may refer to: Education Schools Lahore Grammar School Lanark Grammar School Langley Grammar School Larne Grammar School Leeds Grammar School Leicester Grammar School Limavady Grammar School Loughborough Grammar School, one of the Loughborough Endowed Schools Other Liselere Geçiş Sınavı, the old name for OKS. Local gaming store. A store to play or purchase board games. Entertainment Looking Glass Studios, a defunct computer game company La Grande Sophie, a French singer-songwriter Science Laser guide star, an adaptive optics instrument used in Astronomy Leaky gut syndrome, an intestinal dysfunction LGS Innovations, a high-tech private company and former division of Bell Labs Latitudinal Gradients in Species diversity Lennox–Gastaut syndrome, a type of epilepsy Light Gauge Steel, also called cold-formed steel Software Logitech Gaming Software, a driver style software for Logitech Gaming products