Marcus Aurelius Valerius Maxentius (c. 283 – 28 October 312) was a Roman emperor, who reigned from 306 until his death in 312. Despite ruling in Italy and North Africa, and having the recognition of the Senate in Rome, he was not recognized as a legitimate emperor by his fellow emperors.

He was the son of former Emperor Maximian and the son-in-law of Emperor Galerius. The latter part of his reign was preoccupied with civil war, allying with Maximinus against Licinius and Constantine. The latter defeated him at the Battle of the Milvian Bridge in 312, where Maxentius, with his army in flight, purportedly perished by drowning in the Tiber river.

Maxentius was the last emperor to permanently reside in Rome. He attempted to embellish, restore and improve the ancient capital, carrying out important building works, including the Temple of the Divine Romulus (dedicated to his deceased son), the Basilica of Maxentius, which was completed by Constantine, the villa and the circus of Maxentius.