- For the Law Agency in the HD Era, see FIB.
The Federal Bureau of Investigation (FBI) is an Agency in the 3D Era, and is based off the real-life FBI law enforcement agency.
GTA III — GTA Vice City Stories The FBI is the third level of law enforcement that pursues the player. The FBI will appear only when the player's wanted level reaches five stars, before the Army on six stars.
FBI Agents wear blue jackets with "FBI" printed on the back in nearly all of the GTA III era games (excluding GTA III itself). In Grand Theft Auto: Vice City Stories they wear black vests over grey t-shirts with "FBI" printed on the back with dark glasses. The FBI agents are well armed in all appearances, and their vehicles are generally extremely fast. The FBI comes with four agents in each car, and since they are well armed and very accurate, they will kill the player extremely quickly if they have an open range. They carry MP5s in all of the GTA III era games except for Grand Theft Auto III, where this weapon is unavailable, and instead they carry AK-47s and pistols (when killed).
- In GTA III, the CIA Agents (guarding the Shoreside Lift Bridge in Marked Man) and Liberty City Port Authority officers (in the hangar from Grand Theft Aero) share the same character polygon as the FBI Agents. However, the CIA Agents wear all black, while the Port Authority have different caps.
- In Grand Theft Auto: San Andreas, some missions have FBI wielding Micro SMGs instead of SMGs. The same case is equivalent to the SWAT in missions wielding SMGs instead of Micro SMGs.
- The FBI Washington in GTA Vice City Stories is the only FBI vehicle in all of the GTA series to be colored white.
- The FBI in GTA Vice City Stories seem to be one of the most hostile in the GTA III era as their blockades will instantly blow up or heavily damage your car on sight. The best way to maneuver through a blockade is to get a bullet-proof car.
- In the GTA III 10th Anniversary Edition, the FBI agents have had the lettering changed from FBI to FIB. This does not apply to the name of the FBI Car, however.
- In GTA IV Era, Rockstar changed the name of the Federal Bureau of Investigation (FBI) into the Federal Investigation Bureau (FIB) for some reason.
- DGSE, the French equivalent.