The Populares (/ˌpɒpjʊˈlɛərz, -jə-, -ˈlrz/; Latin for "favoring the people", singular popularis) were a political faction in the late Roman Republic who favoured the cause of the plebeians (the commoners).

Main leadersTiberius Gracchus
Gaius Gracchus
Gaius Marius
Lucius Cornelius Cinna
Lucius Appuleius Saturninus
Marcus Aemilius Lepidus
Publius Clodius Pulcher
Julius Caesar
Mark Antony
Plebeians' interests
Debt relief
Grain dole
Land reform
Supremacy of Plebeian Council
Supremacy of Tribunes

The Populares emerged as a political group with the reforms of the Gracchi brothers, who were tribunes of the plebs between 133 and 121 BC. Although the Gracchi belonged to the highest Roman aristocracy, being the grandsons of Scipio Africanus, they were concerned for the urban poor, whose dire condition increased the risk of a social crisis at Rome. They tried to implement a vast social program comprising a grain dole, new colonies, and a redistribution of the Ager publicus in order to alleviate their situation. They also drafted laws to grant Roman citizenship to Italian allies, and reform the judicial system to tackle corruption. Both brothers were nevertheless murdered by their opponents, the Optimates—the conservative faction representing the interests of the landed aristocracy, who dominated the Senate. Several tribunes of the plebs later tried to pass the Gracchi's program by using plebiscites (in order to bypass senatorial opposition), but Saturninus and Clodius Pulcher suffered the same fate as the Gracchi. Furthermore, many politicians of the late Republic postured as Populares to enhance their popularity among the plebs, notably Julius Caesar and Octavian (later Augustus), who finally enacted most of the Populares' platform during their rule.

The Populares counted a number of patricians—the most ancient Roman aristocrats—such as Appius Claudius Pulcher, Lucius Cornelius Cinna, and Julius Caesar among their number. They were allied to politicians of lesser status, especially "new men" like Gaius Marius, or Gaius Norbanus (who might have even been a new Roman citizen).