Gaius Memmius (died December 100 BC) was a tribune of the plebs in 111 BC and attacked certain aristocrats on a charge of corrupt relations with Jugurtha. Sallust refers to Memmius as "a man fiercely hostile to the power of the nobles" and states that he gave speeches whipping up the plebs, urging them not to accept the behaviour of the nobles.
In 100 BC, Memmius was a candidate for the consulship of the following year (99 BC), but was slain in a riot, stirred up by his rival the praetor Gaius Servilius Glaucia..
Sallust describes him as an orator, but Cicero had a poor opinion of him.