Heretic may refer to the following:
- Heretics - The outcasts of the Covenant.
- Covenant Separatists - The next outcasts of the covenant which allied with the UNSC to defeat the remaining Covenant Loyalist forces.
- UNSC - The main enemy faction of the Covenant empire which consists of humans.Covenant separatists.
- Insurrectionists/Rebels - Another faction of humans who are also enemies of covenant.
- The Heretic - The first level of Halo 2, composed entirely of cutscenes.
- Heretic (level) - A map in the Halo 3 Mythic map pack DLC.
- The Heretic (Machinima Series) - The prequel to The Codex.
- A Firefight exclusive ranking of an Elite, who usually wield human weapons.