Marcus Calidius

Marcus Calidius ( 64–47 BC) was a Roman politician and orator.

Jerome, in his Chronicon under the year 64 BC, notes that Calidius studied oratory under Apollodorus of Pergamum. He was one of the earliest Atticists in Rome. In 64, he prosecuted Quintus Gallius for , even accusing Gallius, who was defended by Cicero, of trying to poison him. Gallius was acquitted. As a praetor in 57, he helped Cicero return from exile and recover his house. This was probably the occasion on which he delivered his speech De domo Ciceronis, cited by Quintilian in his Institutio Oratoria.

In 52, Calidius defended Titus Annius Milo for the murder of Clodius Pulcher. In his Commentary on the Civil War, Caesar recounts how he appointed him governor of Cisalpine Gaul that same year.