Ochlocracy (Greek: ὀχλοκρατία, okhlokratía; Latin: ochlocratia) or mob rule is the rule of government by mob or a mass of people, or, the intimidation of legitimate authorities. As a pejorative for majoritarianism, it is akin to the Latin phrase mobile vulgus meaning "the fickle crowd", from which the English term "mob" originally was derived in the 1680s.
Ochlocracy is synonymous in meaning and usage to the modern, informal term "", which arose in the 18th century as a colloquial neologism.
Ochlocracy, or mob rule, is often incorrectly equated with tyranny of the majority; however, ochlocracy involves illegal action and does not necessitate a majority.
Polybius (second century BCE) appears to have coined the term in his Histories (6.4.6). He uses it to name the "pathological" version of popular rule—in opposition to the good version, which he refers to as democracy. There are numerous mentions of the word "ochlos" in the Talmud (where "ochlos" refers to anything from "mob", "populace", to "armed guard"), as well as in Rashi, a Jewish commentary on the Bible. The word is recorded in English since 1584, derived from the French ochlocratie (1568), which stems from the original Greek okhlokratia, from okhlos ("mob") and kratos (meaning "rule, power, strength").
Ancient Greek political thinkers regarded ochlocracy as one of the three "bad" forms of government (tyranny, oligarchy, and ochlocracy) as opposed to the three "good" forms of government (monarchy, , and democracy). They distinguished "good" and "bad" according to whether the government form would act in the interest of the whole community ("good") or in the exclusive interests of a group or individual at the expense of justice ("bad").