The iron law of oligarchy is a political theory first developed by the German-born Italian sociologist Robert Michels in his 1911 book Political Parties. It asserts that rule by an elite, or oligarchy, is inevitable as an "iron law" within any democratic organization as part of the "tactical and technical necessities" of the organization.

Robert Michels was a German-born Italian sociologist who contributed to elite theory by describing the political behavior of intellectual elites.