G2 or G-2 may be:

• G2 (Generic Gamers), a Washington State based consortium of game and anime inthusiasts
• G2 (Guatemala), a government secret police in Guatemala in the 1980s
• G2 (Cuba), Cuban intelligence service
• G2 (Glasspar), a fiber-glass body car predating the Kaiser Darrin and Corvette
• G2 (mathematics), a Lie group
• G2 military intelligence officer, a general staff position in the United States Army
• G2 gel pen brand made by the Pilot Pen Corporation
• G2 phase of the cell cycle
• G2 star, a subclass of G-Stellar classification
• Canon PowerShot G2, a digital camera made by Canon Inc.
• County Route G2 (California), also known as Lawrence Expressway
• Gensym G2, a real-time business rules engine platform
• PowerPC G2, aka PowerPC 604 and PowerPC 604e
  • PowerMac G2
  • PowerBook G2
• RealPlayer G2, also known as RealPlayer 8
• The Guardian G2, a supplement of the British newspaper
• Generation 2, the short lived second incarnation of the Transformers toy line
• Gnutella2, the P2P Network
• Group 2 of the periodic table
• Dobrolet Airlines IATA airline designator
• G2 or G-2 Military Intelligence Branch of the Irish Defence Forces (DFI)
• G.II, a German designation for several World War I heavy bombers

• • AEG G.II
  • Gotha G.II