Triarchy, synonym for triumvirate, is a political regime ruled or dominated by three powerful individuals.

Triarchy may also refer to:

• Triarchy (theory), a proposition that there are three fundamental ways of getting things done in organisations: hierarchy, heterarchy and responsible autonomy
• Triarchy of Negroponte, a crusader state established on the island of Euboea

• Triarchy of the Lost Lovers, an album by Rotting Christ
• Triarchic theory of intelligence
• Triumvirate (disambiguation)