The Conflict of the Orders, sometimes referred to as the Struggle of the Orders, was a political struggle between the plebeians (commoners) and patricians (aristocrats) of the ancient Roman Republic lasting from 500 BC to 287 BC in which the plebeians sought political equality with the patricians. It played a major role in the development of the Constitution of the Roman Republic. Shortly after the founding of the Republic, this conflict led to a secession from Rome by Plebeians to the Sacred Mount at a time of war. The result of this first secession was the creation of the office of plebeian tribune, and with it the first acquisition of real power by the plebeians.

At first, only patricians were allowed to stand for election to political office, but over time these laws were revoked, and eventually all offices were opened to the plebeians. Since most individuals who were elected to political office were given membership in the Roman Senate, this development helped to transform the Senate from a body of patricians into a body of both patrician and plebeian aristocrats. This development occurred at the same time that the plebeian legislative assembly, the Plebeian Council, was acquiring additional power. At first, its acts ("plebiscites") applied only to plebeians, although after 339 BC, with the institution of laws by the first plebeian dictator Q. Publilius Philo, these acts began to apply to both plebeians and patricians. The most fundamental change, however, was the granting of tribunicia potestas (tribunician power) in which tribunes of the plebs could veto unfavorable legislation.