The following are known Action Replay Codes for Namco Museum 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
bd86b55a
6b4f2ebe
734499e3
1e4426a9

Galaxian: Infinite Lives
ea907865
9f51c018

Ms Pacman: Infinite Lives
ee03a379
b803f5bd

Pole Position: Infinite Time
a25437d1
1f86033c

Dig Dug: Infinite Lives
5dbe33a0
c2f8f2dc

Galaga: Infinite Lives
4cb1b5b4
bcf1db3e