Marcellus was praetor apparently in 80 BC, and afterwards succeeded M. Aemilius Lepidus in the government of Sicily.
Statues were erected to him in almost every city of the island; and the festival of the Marcellea already instituted in honor of his ancestor, Marcus Claudius Marcellus, was now renewed in his favor.
Cicero, throughout his speeches against Verres, dwelled frequently upon the administration of Marcellus, as affording the most striking contrast to that of the accused.
Marcellus held the office of augur, in which Cicero was one of his colleagues, and is cited by him as one of those who regarded the whole science of augury as a merely political institution.
He lived to see his son, also called Gaius Claudius Marcellus, elected consul for the year 50 BC; and on that occasion Cicero wrote him a letter of congratulation.