He started his political career as curule aedile in 195 BC. When he was praetor (193 BC) he served with distinction in Spain, and as consul in 189 BC he completely broke the power of the Aetolian League. On his return to Rome, Nobilior celebrated a triumph (of which full details are given by Livy) remarkable for the magnificence of the spoils exhibited. On his Aetolian campaign he was accompanied by the poet Ennius, who made the capture of Ambracia, at which he was present, the subject of one of his plays. For this Nobilior was strongly opposed by Cato the Censor, on the ground that he had compromised his dignity as a Roman general. In 179 BC he was appointed censor together with Marcus Aemilius Lepidus.
He was a great enthusiast for Greek art and culture, and introduced many of its masterpieces into Rome, amongst them the picture of the Muses by Zeuxis from Ambracia.