The following are known Action Replay Codes for F-Zero: GP Legend 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
3e6dcacb
2f2ae940
8c15f8b0
035f2bd6

Infinite Power
17c947ee
fd286430

Sel+R – Instant Win
405d56e9
1e55d0bb
bd77f207
64e93ee0

Sel+L – Kill All
d45dec8d
baa479f7
8e9a15c2
b323ed4a
c535d6ab
3a753563

Story Mode Complete
e41e9d51
3c99543a
78eee77e
0bad0e40
fded0e0b
596ea505

All Zero Tests Open
c7aab12c
e8c0bb0b

Zero Tests Complete
e9eea70e
d366de74
de436d5e
98fadfa6

All Modes/Cups/Etc
5742f0f9
28626452