The following are known Action Replay Codes for Gradius 3 on Super Nintendo Entertainment System (SNES).

• Have Two Way Missiles – These are probably the most useful missiles in the game but cannot normally be combined with other options.
  7E00B40D
• Keep the Option Select over the Shield Ready for a new one.
  7E00B006
• Unlimited Lives, but do not enable the Action Replay until the game is running.
  7E007C03
• Infinite Lives
  00BCF0EA
• Infinite Credits
  00D230AD
• Start with 7 Credits
  7E1E0607
• Start with 7 Credits
  C5F3A007
• Start with 7 Credits
  D5C3FDF0
• Infinite Lives
  00BCF0EA
  00BCF1EA
• Weapons status gauge remains at current level after a weapon is selected
  00D95DEA
  00D95EEA