Brutus, Marcus Junius (85?–42 B.C. ), a Roman leader who was one of the assassins of Julius Caesar. In 49 B.C. Brutus joined Pompey in an attempt to overthrow Caesar. But after Caesar destroyed Pompey's army at Pharsalus, Greece, he pardoned Brutus and made him governor of Cisalpine Gaul in 46 and praetor, or magistrate, of Rome in 44. Nevertheless, in 44 Brutus joined Gaius Cassius Longinus and others in the plot that brought about Caesar's death.

Mark Antony aroused the Romans against the assassins, who fled. In 42 Brutus and Cassius were defeated at Philippi. Macedonia, by Antony and Octavian (Augustus), grand-nephew of Caesar. Brutus killed himself with his sword.

Brutus is a leading character in Shakespeare's play Julius Caesar.