Lucius Calpurnius Piso Caesoninus was a Roman senator and the father-in-law of Julius Caesar through his daughter Calpurnia. He was reportedly a follower of a school of Epicureanism that had been modified to befit politicians, as Epicureanism itself favoured withdrawal from politics. Piso was consul in the year 58 BC with Aulus Gabinius as his colleague.

Calpurnia was either the third or fourth wife of Julius Caesar, and the one to whom he was married at the time of his assassination. According to contemporary sources, she was a good and faithful wife, in spite of her husband's infidelity; and, forewarned of the attempt on his life, she endeavored in vain to prevent his murder.