His mother was Pompeia, the sister to consul Gnaeus Pompeius Strabo, father of Pompey Magnus, a member of the First Triumvirate with Julius Caesar and Marcus Licinius Crassus.
During the consulship of Julius Caesar in 59 BC, Balbus was appointed along with Pompey to a board of commissioners under a Julian Law to divide estates in Campania among the commoners.
He married Julia Minor, the younger of the two elder sisters of the dictator Julius Caesar.
Julia bore him two or more daughters and possibly a son named Marcus Atius Balbus.
[1] One of the daughters married Gaius Octavius and became the mother of Octavia Minor (fourth wife of triumvir Mark Antony) and of the first Roman emperor Augustus.