Roman politician who supported the agrarian reforms of the tribune Tiberius Gracchus. Brother of the orator and jurist Publius Mucius Scaevola, Crassus was adopted into the gens (“clan”) of the Licinii. He was the father-in-law of the reformer Gaius Gracchus. When Tiberius Gracchus was murdered in 133, Crassus took the reformer's place on the Gracchan land commission and consistently opposed the conservative statesman Scipio Aemilianus. Crassus was elected pontifex maximus (high priest), and in 131 he was made consul.

In 130 Crassus—the first pontifex maximus to undertake a military command outside Italy—was defeated and killed by Aristonicus of Pergamum, in northwestern Asia Minor.