A member of the plebeian gens Aurelia, Cotta was elected tribune of the plebs in 154 BC.
[2] In 144 BC, Cotta was made the consul of Rome together with Servius Sulpicius Galba where the two entered into a dispute before the Roman senate about who would be the leader of the contemporary war against Viriathus on the Iberian Peninsula.
Although it appears that Cotta may have indeed been guilty, he was absolved of any wrongdoing as the judges wanted to avoid the semblance of his condemnation due to Scipio's great influence.
Cicero stated that Cotta was considered a veterator, saying that he was a capable man in both his business and personal life.
Through his son's daughter, Aurelia Cotta, he was the great-grandfather of the famous dictator Gaius Julius Caesar and great-great-grandfather of the first Roman Emperor Augustus.