List of Halo 3 and Halo 3: ODST medals
From Halopedia, the Halo wiki
Medals are preset rewards or bonuses given in Halo 3's Multiplayer and Campaign modes, and Halo 3: ODST's Campaign and Firefight modes, when players perform some action, usually involving the killing of enemies or rival players. There are a total of 61 medals in Halo 3 and 34 medals in Halo 3: ODST.
These are the medals awarded in Halo 3 and Halo 3: ODST.
General multiplayer medals
Objective multiplayer medals
Halo 3: ODST
These are the medals awarded in Halo 3: ODST's Firefight mode and in the campaign (if scoring is turned on).
Halo 3 campaign medals