Lucius Antonius (1st century BC) was the younger brother and supporter of Mark Antony, a Roman politician. Another Lucius Antonius was a grandson to Mark Antony.

Lucius was son of Marcus Antonius Creticus, son of the rhetorician Marcus Antonius Orator executed by Gaius Marius' supporters in 86 BC, and Julia Antonia, a cousin of Julius Caesar. Together with his older brothers Mark Antony and Gaius Antonius, he spent his early years roaming through Rome in bad companies. Plutarch refers the untamed life of the youths and theirs friends, frequenting gambling houses and drinking too much.

Lucius was always a big supporter of Mark Antony. In 44 BC, the year of Antony's consulship and Julius Caesar's assassination, Lucius was a tribune of the plebs. In 41 BC, was consul with Publius Servilius Vatia as his senior partner. In this year, he assisted Mark Antony's wife, Fulvia, in the raising of an eight legion army to fight against Octavian's unpopular policies. After a successful occupation of Rome, they ended up besieged in Perusia in the winter of 41/40 BC, where they were forced to surrender by starvation. Octavian destroyed the city but spared the rebellion's leaders: Fulvia and Lucius were exiled.

Lucius Antonius was the only child to Iullus Antonius and Claudia Marcella Major. He was born in Rome either in 20BC or 19BC and was raised there. Lucius was the oldest grandson to Octavia, (sister of Caesar Augustus), oldest grandchild to Mark Antony and grandson to Fulvia. Among his ancestors, are Publius Cornelius Scipio Africanus Major who defeated Hannibal, his daughter Cornelia Africana and her sons Tiberius Gracchus and Gaius Gracchus.

Around 2BC, his father was charged by his great-uncle adultery with his daughter Julia Caesaris. Iullus was charged and was exiled where he later died. Being ashamed of his father Lucius asked Augustus to send him into exile. Unwillingly, Augustus agreed.

In exile he was treated honorly and was sent to Marseille, France. There he became a praetor and studied law, where he became a clerk. He was never married. Lucius died in 25AD. Lucius received a state funeral and was laid in The Tomb of the Octavii.