This is a complete list of all achievements in Halo 3. New armour for use in multiplayer modes is unlocked by completing these achievements - a full list of these to do so will become available soon.

Halo 3 - Achievements List

Name	Description	Points
1. Landfall	Finish the first mission of the Campaign on Normal, Heroic, or Legendary.	20 Points
2. Holdout	Finish the second mission of the Campaign on Normal, Heroic, or Legendary.	20 Points
3. The Road	Finish the third mission of the Campaign on Normal, Heroic, or Legendary.	20 Points
4. Assault	Finish the fourth mission of the Campaign on Normal, Heroic, or Legendary.	30 Points
5. Cleansing	Finish the fifth mission of the Campaign on Normal, Heroic, or Legendary.	30 Points
6. Refuge	Finish the sixth mission of the Campaign on Normal, Heroic, or Legendary.	30 Points
7. Last Stand	Finish the seventh mission of the Campaign on Normal, Heroic, or Legendary.	40 Points
8. The Key	Finish the eighth mission of the Campaign on Normal, Heroic, or Legendary.	40 Points
9. Return	Finish the final mission of the Campaign on Normal, Heroic, or Legendary.	50 Points
10. Campaign Complete: Normal	Finish the Campaign on Normal.	125 Points
11. Campaign Complete: Heroic	Finish the Campaign on Heroic (unlocks achievement for Normal, if not earned).	125 Points
12. Campaign Complete: Legendary	Finish the Campaign on Legendary (unlocks achievements for Normal and Heroic, if not earned).	125 Points
13. Iron	Finish the Campaign on Normal, Heroic, or Legendary, then find and claim this skull.	10 Points
14. Black Eye	Claim the skull.	10 Points
15. Tough Luck	Claim the skull.	10 Points
16. Catch	Claim the Black Eye skull.	10 Points
17. Fog	Claim the skull.	10 Points
18. Famine	Claim the skull.	10 Points
19. Thunderstorm	Claim the skull.	10 Points
20. Tilt	Claim the skull.	10 Points
21. Mythic	Claim the skull.	10 Points
22. Spartan Program Recruit	Win your first game in matchmaking to sign up for the Spartan Program (Online).	10 Points
23. UNSC Spartan	Earn your Sergeant rating to be recognized as a true Spartan (Online).	15 Points
24. Spartan Officer	Advance to the Spartan Officer ranks (Online).	25 Points
25. Two for One	Score a Double Kill with a single spartan laser shot in a ranked free for all playlist (Online).	5 Points
26. Too Close to the Sun	Destroy an enemy banshee with the spartan laser or missile pod in a ranked playlist or in campaign.	5 Points
27. Triple Kill	Kill 3 enemies within 4 seconds of one another in a ranked free for all playlist (Online).	5 Points
28. Overkill	Kill 4 enemies within 4 seconds of one another in a ranked free for all playlist (Online).	5 Points
29. Lee R Wilson Memorial	Score 5 grenade sticks in any ranked free for all playlist (Online).	5 Points
30. We're in for some Chop	Destroy an enemy vehicle with equipment in a ranked playlist or in campaign.	5 Points
31. Killing Frenzy	Kill 10 enemies without dying in any ranked free for all playlist (Online).	5 Points
32. Steppin' Razor	Score a Triple Kill with the sword in a ranked free for all playlist (Online).	5 Points
33. Mongoose Mowdown	Splatter an enemy with the mongoose in a ranked free for all playlist (Online).	5 Points
34. Up Close and Personal	Kill 5 enemies by melee or assassination in a ranked free for all playlist (Online).	5 Points
35. Fear the Pink Mist	Kill 5 enemies with the needler in a ranked free for all playlist or in campaign.	5 Points
36. Headshot Honcho	Kill 10 enemies with headshots in a ranked free for all playlist or in campaign.	5 Points
37. Used Car Salesman	Destroy a vehicle that has three enemies in it in a ranked playlist or in campaign.	5 Points
38. Marathon Man	Locate and access all Terminals in the Campaign.	40 Points
39. MVP	Earn the MVP in any ranked playlist (Online).	5 Points
40. Maybe Next Time Buddy	Board the same vehicle within 10 seconds after being boarded in any free for all playlist (Online).	5 Points
41. Demon	Score over 15,000 Points in the Campaign meta-game on the second mission.	10 Points
42. Guerilla	Score over 15,000 Points in the Campaign meta-game on the first mission.	10 Points
43. Cavalier	Score over 15,000 Points in the Campaign meta-game on the third mission.	10 Points
44. Askar	Score over 15,000 Points in the Campaign meta-game on the fourth mission.	10 Points
45. Exterminator	Score over 15,000 Points in the Campaign meta-game on the fifth mission.	10 Points
46. Ranger	Score over 50,000 Points in the Campaign meta-game on the sixth mission.	10 Points
47. Vanguard	Score over 50,000 Points in the Campaign meta-game on the seventh mission.	10 Points
48. Orpheus	Score over 15,000 Points in the Campaign meta-game on eighth mission.	10 Points
49. Reclaimer	Score over Points in the Campaign meta-game on the final mission.	10 Points