Counter-terrorism unit of the German Federal Police. Inherited its name from the "Grenzschutzgruppe 9" (Federal Border Guards Group 9). The unit was established in response to the 1972 Munich Olympics incident, wherein the German government failed to prevent the death of several athletes at the hands of the "Black September" terrorist group.

In the 1990s, Solid Snake battled ex-GSG9 mercenary, Fire Trooper, in Outer Heaven.