Optimates ('Good Men') were the aristocratic faction of the later Roman Republic. They wished to limit the power of the popular assemblies and extend the power to the Senate, which was viewed as more stable and more dedicated to the well-being of Rome. The optimates favored the nobiles (noble families) and opposed the ascension of 'new men' (plebeians, usually provincials, whose family had no former political experience) into Roman politics. The irony was that the major champion of the later optimates, Marcus Tullius Cicero, was himself a new man.

In addition to their political aims, the optimates opposed the extension of Roman citizenship beyond Italy (and even opposed granting citizenship to most Italians). They generally favored high interest rates, opposed the expansion of Hellenistic culture into Roman society, and worked hard to provide land for discharged soldiers (the belief being that happy soldiers were less likely to rise up in support of rebelling generals).

The optimate cause reached its peak under the dictatorship of Lucius Cornelius Sulla Felix (81 BC-79 BC). During his reign, the Assemblies were stripped of nearly all power, the Senate membership was raised from 300 to 600, thousands of soldiers were settled in northern Italy, and an equally large number of populares were executed via proscription lists. However, after Sulla's resignation and subsequent death, many of their policies were gradually reversed.

Besides Cicero and Sulla, notable optimates included Cato the Elder and Cato the Younger, Titus Annius Milo, Marcus Junius Brutus and (generally excluding his Triumvirate), Pompey.