Gaius Memmius (incorrectly called Gemellus, "The Twin"), Roman orator and poet, tribune of the people (66 BC), patron of Lucretius and acquaintance of Catullus.
At first a strong supporter of Pompey, he quarrelled with him, and went over to Caesar, whom he had previously attacked. In 54, as candidate for the consulship, he lost Caesar's support by revealing a scandalous transaction in which he and his fellow candidate had been implicated.
Being subsequently condemned for illegal practices at the election, he withdrew to Athens, and afterwards, to Mytilene. He died about the year 49. He is remembered chiefly because it was to him that Lucretius addressed the De rerum natura, perhaps with the idea of making him a convert to the doctrines of Epicurus. It appears from Cicero that he possessed an estate on which were the ruins of Epicurus' house, and that he had determined to build on the site a house for himself. According to Ovid he was the author of erotic poems. He possessed considerable oratorical abilities, but his contempt for Latin letters and preference for Greek models impaired his efficiency as an advocate.
Gaius Memmius was married to Cornelia Fausta, the daughter of Lucius Cornelius Sulla. They had at least one son, Gaius Memmius, suffect consul in 34 BC.