IGS may stand for:

Computers/Video Games

• IGS Go server
• iGamespot, former professional MLG Halo 2 team
• Information Gateway Services, an Internet Service Provider
• Information Global Service, video game company
• Initial Graphics Exchange Specification and the file extension thereof (.igs)
• Interactive geometry software
• International Games System
• Interactive Gaming Software, an US based computer game distributor

Technology

• Inertial guidance system
• Instrument Guidance System
• Insertion Gain Smoothing, a technique used in Signal Processing, primarily with regards to Acoustic Technologies
• Image guided surgery or computer assisted surgery
• Information Gathering Satellites, Japanese military reconnaissance satellites

Science

• Institute of General Semantics
• Institute of Geological Sciences
• International Glaciological Society

Schools

• International Grammar School, Sydney.
• Ilkley Grammar School
• Ipswich Grammar School
• Ivanhoe Grammar School
• Islington Green School

Other

• Irish Georgian Society
• International Graduates Scheme, a UK immigration scheme
• The ISO 639-3 code for Glosa constructed language