Marcus Calpurnius Bibulus was a politician of the late Roman Republic. An opponent of Julius Caesar, he was consul alongside Caesar in 59 BC, and fought against him in the civil war that broke out between Caesar and Pompey in 49 BC.

Bibulus was married twice. From the first marriage he had three sons, the later statesman Lucius Calpurnius Bibulus. His two eldest sons were killed in Egypt by some of the soldiery which Aulus Gabinius had left there after having restored Ptolemy Auletes to the throne.

His second wife was Cato's daughter Porcia, whom he married sometime between 58 and 53 BC. He may had a daughter called Calpurnia who was the first wife of Roman Senator Marcus Valerius Messalla Corvinus.

Gift med
Porcia Catonis av Porcii, född -72 i Roma, Lazio, Italien, död -43 i Roma, Lazio, Italien.

Barn:
Calpurnia av Calpurnii, född -55, död -18