The following are known Action Replay Codes for Jimmy Neutron: Boy Genius on Nintendo Game Boy Advance (GBA).
These codes were also known as GameShark Codes and in most cases will work on both devices.

These codes are for the U.S. version of the game.

Master Code – Must Be On
94279d40
7724265d
6d2e27e9
b615cf17

Invincibility
29cd4de0
b8455cc1

Infinite Health
18acc431
a44dcb91

Infinite Lives
ae9bf5d4
7bf75f48

Infinite Fuel
73445d12
0690b5b8

Infinite Shrink Ray/Laser
d6283aa5
dfbb6615

Max Score
7ca6f683
5691d96a

Always 100%
995045a3
5ad909c9