Spartacus (/ˈspɑːrtəkəs/; c. 103 – 71 BC) was a Thracian gladiator who was one of the escaped slave leaders in the Third Servile War, a major slave uprising against the Roman Republic.

Historical accounts of his life come primarily from Plutarch and Appian, who wrote more than a century after his death. Plutarch's Life of Crassus and Appian's Civil Wars provide the most detailed accounts of the slave revolt. Although Spartacus is a significant figure in Roman history, no contemporary sources exist, and all accounts are written significantly later, by persons not directly involved, and without perspectives of slaves or eyewitnesses. Little is known about him beyond the events of the war, and the extant accounts are contradictory. All sources agree, however, that he was a former gladiator and accomplished military leader.

Spartacus is described to be born near the Strymon river, in Thrace (now known as Bulgaria), possibly from the Maedi tribe. Before his enslavement and use as a gladiator, he served as a soldier with the Romans. His revolt began in 73 BC when, along with about 70 other gladiators, he escaped a gladiatorial school near Capua. Despite their initially small numbers, Spartacus's forces were able to defeat several Roman military units and swell their ranks to an estimated 70,000 enslaved people and others. Spartacus proved himself a capable tactician despite the dearth of formal military training among his followers, who were a diverse mix.

The rebellion posed a significant challenge to Roman authority, prompting a series of military campaigns against it. Ultimately, Marcus Licinius Crassus was tasked with suppressing the revolt. Despite initial successes and attempts to negotiate and escape to Sicily, Spartacus's forces were defeated in 71 BC. Spartacus was presumed killed in the final battle, although his body was never found. In the aftermath of the rebellion, 6,000 captured rebels were crucified along the Appian Way.

Spartacus's motives remain a subject of debate. Some sources suggest he aimed to escape Italy, while others hint at broader social reform goals. His legacy has endured, inspiring cultural works and becoming a symbol of resistance and revolutionary movements, influencing such figures as Karl Marx and Toussaint Louverture. The rebellion, interpreted as an example of oppressed people fighting for their freedom against a slave-owning oligarchy, has been portrayed in literature, television, and film. The philosopher Voltaire described the Third Servile War as "the only just war in history".^{[better source needed]} Although this interpretation is not specifically contradicted by classical historians, no historical account claims that the goal was to end slavery in the Republic.

There are two main sources on Spartacus, both of which were written a century or more after his death: Plutarch of Chaeronea (46 AD - 119 AD) and Appian of Alexandria (95 AD – AD 165). The specific works are Life of Crassus (early Second Century AD) by Plutarch and Civil Wars (early to mid Second Century AD) by Appian. Out of all surviving sources on Spartacus, none was written by eyewitnesses and are all later reconstructions; nor were the sources written by slaves or former slaves, and the earliest source was at least a generation after the war.

The Greek essayist Plutarch describes Spartacus as "a Thracian of Nomadic stock", in a possible reference to the Maedi tribe. Appian says he was "a Thracian by birth, who had once served as a soldier with the Romans, but had since been a prisoner and sold for a gladiator".

Florus described him as one "who, from a Thracian mercenary, had become a Roman soldier, that had deserted and became enslaved, and afterward, from consideration of his strength, a gladiator". The authors refer to the Thracian tribe of the Maedi, which occupied the area on the southwestern fringes of Thrace, along its border with the Roman province of Macedonia, in what is now south-western Bulgaria. Plutarch also writes that Spartacus's wife, a prophetess of the Maedi tribe, was enslaved with him.