These GTA 3 cheats are listed by the GTA Wiki community. Enter them during play; each table is for the platform named above it.

EffectPS2PC/AndroidXbox
Replenish player health; if driving a vehicle, its health will also be replenishedR2, R2, L1, R1, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad UpGESUNDHEITBlack, Black, Left Trigger (LT), Right Trigger (RT), D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up
Replenish player armorR2, R2, L1, L2, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad UpTURTOISE (1.0 version) TORTOISE (1.1 version)Black, Black, Left Trigger (LT), White, D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up
Acquire all weapons Note: For this cheat on the Android version, there is no confirmation message. Note: Entering this cheat numerous times will give the player infinite ammo.R2, R2, L1, R2, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad UpGUNSGUNSGUNSBlack, Black, Left Trigger (LT), Black, D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up
Acquire $250,000 in cashR2, R2, L1, L1, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Right, D-Pad UpIFIWEREARICHMANBlack, Black, Left Trigger (LT), Left Trigger (LT), D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up
Spawn a Rhino (On Android, instead of a tank, the first time the cheat is used a Landstalker spawns, after which random cars are spawned)Circle, Circle, Circle, Circle, Circle, Circle, R1, L2, L1, Triangle, Circle, TriangleGIVEUSATANKB, B, B, B, B, B, Right Trigger (RT), White, Left Trigger (LT), Y, B, Y
Blow up/explode/destroy all vehicles, excluding police-controlled helicopters and NPC DodoL2, R2, L1, R1, L2, R2, Triangle, Square, Circle, Triangle, L2, L1BANGBANGBANGWhite, Black, Left Trigger (LT), Right Trigger (RT), White, Black, Y, X, B, Y, White, Left Trigger (LT)
Low gravity for cars, cars control like airborne planesD-Pad Right, R2, Circle, R1, L2, D-Pad Down, L1, R1CHITTYCHITTYBBD-Pad Left, Black, B, Right Trigger (RT), White, D-Pad Down, Left Trigger (LT), Right Trigger (RT)
Only the wheels of cars are visibleL1, L1, Square, R2, Triangle, L1, TriangleANICESETOFWHEELSLeft Trigger (LT), Left Trigger (LT), X, Black, Y, Left Trigger (LT), Y
Increase grip on ground, boost jump ability in all cars, disables unique stunt jumpsR1, L1, R2, L1, D-Pad Left, R1, R1, TriangleCORNERSLIKEMADRight Trigger (RT), Left Trigger (LT), Black, Left Trigger (LT), D-Pad Left, Right Trigger (RT), Right Trigger (RT), Y
Increase wanted level by two starsR2, R2, L1, R2, D-Pad Left, D-Pad Right, D-Pad Left, D-Pad Right, D-Pad Left, D-Pad RightMOREPOLICEPLEASEBlack, Black, Left Trigger (LT), Black, D-Pad Left, D-Pad Left, D-Pad Left, D-Pad Left, D-Pad Left, D-Pad Left
Remove all wanted levelR2, R2, L1, R2, D-Pad Up, D-Pad Down, D-Pad Up, D-Pad Down, D-Pad Up, D-Pad DownNOPOLICEPLEASEBlack, Black, Left Trigger (LT), Black, D-Pad Up, D-Pad Down, D-Pad Up, D-Pad Down, D-Pad Up, D-Pad Down
Light cloudsL1, L2, R1, R2, R2, R1, L2, TriangleSKINCANCERFORMELeft Trigger (LT), White, Right Trigger (RT), Black, Black, Right Trigger (RT), White, Y
Stormy weatherL1, L2, R1, R2, R2, R1, L2, CircleILOVESCOTLANDLeft Trigger (LT), White, Right Trigger (RT), Black, Black, Right Trigger (RT), White, B
Foggy weatherL1, L2, R1, R2, R2, R1, L2, CrossPEASOUPLeft Trigger (LT), White, Right Trigger (RT), Black, Black, Right Trigger (RT), White, A
Overcast weatherL1, L2, R1, R2, R2, R1, L2, SquareILIKESCOTLANDLeft Trigger (LT), White, Right Trigger (RT), Black, Black, Right Trigger (RT), White, X
Increase game speed by 2, up to x4 normal speedTriangle, D-Pad Up, D-Pad Right, D-Pad Down, Square, L1, L2TIMEFLIESWHENYOUY, D-Pad Up, D-Pad Left, D-Pad Down, X, Left Trigger (LT), White
Decrease game speed by half, down to x0.25 normal speedTriangle, D-Pad Up, D-Pad Right, D-Pad Down, Square, R1, R2BOOOOORINGY, D-Pad Up, D-Pad Left, D-Pad Down, X, Right Trigger (RT), Black
Speed up game clockCircle, Circle, Circle, Square, Square, Square, Square, Square, L1, Triangle, Circle, TriangleMADWEATHERB, B, B, X, X, X, X, X, Left Trigger (LT), Y, B, Y
Pedestrian riot Note: Once the cheat is activated for the first time, it will cause a permanent but irreversible in-game effect, thus making the cheat impossible to be deactivated.D-Pad Down, D-Pad Up, D-Pad Left, D-Pad Up, Cross, R1, R2, L2, L1ITSALLGOINGMAAADD-Pad Down, D-Pad Up, D-Pad Left, D-Pad Up, A, Right Trigger (RT), Black, White, Left Trigger (LT)
Pedestrians attack Claude Note: Once the cheat is activated for the first time, it will cause a permanent but irreversible in-game effect, thus making the cheat impossible to be deactivated.D-Pad Down, D-Pad Up, D-Pad Left, D-Pad Up, Cross, R1, R2, L1, L2NOBODYLIKESMED-Pad Down, D-Pad Up, D-Pad Left, D-Pad Up, A, Right Trigger (RT), Black, Left Trigger (LT), White
Pedestrians (except prostitutes and street criminals) carry weaponsR2, R1, Triangle, Cross, L2, L1, D-Pad Up, D-Pad DownWEAPONSFORALLBlack, Right Trigger (RT), Y, A, White, Left Trigger (LT), D-Pad Up, D-Pad Down
Play as pedestrian Note: Re-type the cheat again very quickly and the player model will change back to Claude. Note: Typing the code in the Android mobile port causes the game to crash.D-Pad Right, D-Pad Down, D-Pad Left, D-Pad Up, L1, L2, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad RightILIKEDRESSINGUPD-Pad Left, D-Pad Down, D-Pad Left, D-Pad Up, Left Trigger (LT), White, D-Pad Up, D-Pad Left, D-Pad Down, D-Pad Left
Gore mode Note: For this cheat, there is no confirmation message.Square, L1, Circle, D-Pad Down, L1, R1, Triangle, D-Pad Right, L1, CrossNASTYLIMBSCHEATX, Left Trigger (LT), B, D-Pad Down, Left Trigger (LT), Right Trigger (RT), Y, D-Pad Left, Left Trigger (LT), A

Cheat tables from the GTA Wiki, shared under CC BY-SA 3.0.